- Email: [email protected]
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cal scale. Thus, the particle might be placed on a polished salt plate and extracted with droplets of ether delivered from a capillary pipette with the diameter of a hair. If the droplets are drawn off to the side with a tungsten needle, before they evaporate, a crescent-shaped droplet of the plasticizer will form there and the infrared spectrum can be quickly collected. The extracted particle might now be pressed to a thin film and its infrared spectrum obtained. Inorganic spectral peaks in the particle will be easier to interpret if it is transferred to a polarizing microscope. Many inorganic fillers and pigments, such as talc, calcite, quartz and titanium dioxide, can be readily identified on the basis of their optical properties. If necessary, to complete the interpretation, the particle can be washed free of index of refraction oil and mounted on a polished beryllium plate for EDS spectroscopy to confirm the elemental composition of the fillers. This hypothetical problem illustrates the advantages of an analytical approach, based on the utilization of both microchemistry and modern instrumentation, for the analysis or identification of microscopic items of evidence. See also: Analytical Techniques: Spectroscopy: Basic Principles. Serology: Blood Identification; Bloodstain Pattern Analysis. Analytical Techniques: Spectroscopic Techniques.
Further Reading Alimarin I and Petrikova N (1964) Inorganic Ultramicroanalysis. New York: Pergamon.
Amelink F (1962) Rapid Microchemical Identification Methods in Pharmacy and Toxicology. Amsterdam: Netherlands University Press. Benedetti-Pichler AA (1964) Identification of Materials via Physical Properties, Chemical Tests and Microscopy. New York: Springer. Chamot EM (1940) Handbook of Chemical Microscopy: Vol. II: Chemical Methods and Inorganic Qualitative Analysis. 2nd edn. New York: Wiley. Cheronis ND and Entrikin JB Semicro Qualitative Organic Analysis. The Systematic Identification of Organic Compounds, 2nd edn. New York: Interscience. Clarke EGC (1969, 1975) Isolation and Identification of Drugs in Pharmaceuticals, Body Fluids and PostMortem Material, vol. 1 (1969) and vol. 2 (1975). London: Pharmaceutical Press. Feigl F (1966) Spot Tests in Organic Analysis, 7th edn. Amsterdam: Elsevier. Feigl F (1972) Spot Tests in Inorganic Analysis, 6th edn. Amsterdam: Elsevier. Fulton CC (1969) Modern Microcrystal Tests for Drugs. The Identification of Organic Compounds by Microcrystalloscopic Chemistry. New York: Wiley-Interscience. Geilman W von (1954) Bilder zur Qualitativen Mikroanalyse Anorganischer Stoffe. Weinheim: Verlag Chemie. Jungreis E (1997) Spot Test Analysis Clinical, Environmental, Forensic and Geochemical Applications, 2nd edn. New York: Wiley-Interscience. Palenik SJ (1979) Microchemical reactions in particle identification. In: McCrone WC, Delly JG and Palenik SJ (eds) The Particle Atlas, 2nd edn, pp. 1174±1175. Ann Arbor: Ann Arbor Science. Schneider FL (1964) Qualitative Organic Microanalysis. Cognition and Recognition of Organic Compounds. New York: Academic Press.
Microscopy see Analytical Techniques: Microscopy. Microchemistry. Microtrace see Dust.
MODUS OPERANDI B E Turvey, Knowledge Solutions LLC, Watsonville, CA, USA Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0575
Introduction Modus operandi (MO) is a Latin term that means `a method of operating'. It is used by law enforcement agencies to refer to a criminal's pattern of behavior,
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or his or her way of committing crime. It is by understanding a criminal's MO behavior that most of those in law enforcement investigate and link criminal cases. This investigative approach has evolved from the use of criminal informants and highly experienced detectives, into the additional use of criminal database systems. The use of MO and criminal databases to link cases is but one of several important investigative methods available to law enforcement, and is separate from the concept of offender `signature'.
Definitions
Understanding Criminal Behavior
. to protect identity . to ensure success . to facilitate escape
Law enforcement has long held to the belief that understanding the methods criminals use to commit crime is the best way of searching for, and ultimately apprehending, them. This has traditionally required that detectives be a living encyclopedia of criminal cases and criminal behaviors, or that they learn to utilize the knowledge and experience of known criminals to inform their investigations. A strong belief in this way of approaching the process of criminal investigation was well demonstrated in France, in 1817, when a former convict named Eugene Vidocq, who had been working as a police spy, was assigned by the government to form a Brigade de SuÃreteÂ. He organized and led this group of detectives, mostly former criminals themselves, as it grew from a mere four to 28 in number. Vidocq and his detectives were paid according to the number of criminals that they apprehended. Within their first year, the group had made more than 750 arrests. This led some to believe that Vidocq and his detectives were a perfect solution to the local criminal problem; they understood how criminals operated, had insights into their habits and methods of operation, and were putting that knowledge to work for the good of the state. However, others suspected that Vidocq and his detectives committed many of the crimes themselves and then framed known criminals or undesirables in order to close out the cases. This suspicion was never proven, however, and Vidocq enjoys a largely favorable historical place as the first, and very successful, chief of the French SuÃrete Nationale. Whether or not Vidocq was a master detective or merely continued his criminal career through the SuÃreteÂ, a philosophy of criminal investigation emerged. To understand criminals, to develop competent investigative strategies, to link their crimes and to successfully apprehend them, detectives needed to understand the particular methods criminals used to commit their crimes. This is an investigative philosophy that survives on an international level, in one form or another, to the present day.
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Modus operandi has been defined as the actions taken by a criminal to perpetrate a crime successfully. A criminal's MO is comprised of learned behaviors that can evolve and develop, as they become more sophisticated and more confident. It is through analyzing MO behaviors that law enforcement agencies most commonly investigate and link crimes to a specific offender. A criminal's MO behavior is functional in nature. It generally serves any of three purposes for the offender:
General types of MO behaviors include, but are not limited to: . offense location selection (i.e. in a public park, on a school campus, or in a victim's residence, etc.); . involvement of a victim during a crime; . use of a weapon during a crime; . use of restraints to control the victim during a crime; . offender precautionary acts (i.e. wearing a mask, gloves, covering the victim's eyes during an attack, wearing a condom during a rape, forcing the victim to bathe after a sexual attack, etc.); . offender transportation to and from the crime scene (i.e. use of a bicycle, use of a motorized vehicle, walking, etc.). The criminal's MO, evidenced by MO behavior, is not the same thing as a criminal's motive, which is their reason for committing the crime. A criminal's motives are evidenced by signature behaviors that suggest overall signature aspects, or motivational aspects to the crime. Signature behaviors are those that satisfy the offender's emotional and psychological needs. They are often specialized behaviors, typically not necessary for the completion of the crime, and tend to show less evolution across offenses than MO behavior.
Influences on Modus Operandi A criminal's MO behavior is learned, and therefore dynamic and malleable. This is because MO behavior is affected by time, and can change as the criminal discovers that some of the things done during a crime are more effective than others. Criminals can subsequently recognize these effective actions, repeat them in future offenses, and become more skillful, refining their overall MO. However, behavior may also change due to a criminal's deteriorating mental state, due to
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the influence of controlled substances, and/or due to increased confidence that law enforcement will not successfully apprehend them. These things may cause a criminal's MO to become less skillful, less competent and more careless. Common ways that criminals can learn how to commit crime more skillfully are by gaining more experience, building confidence through success and/ or having more contact with the criminal justice system. Being arrested just once may teach an offender an invaluable lesson about how to avoid detection by law enforcement in the future. Further still, and with some great irony, a prison term in the United States is referred to by some, in both law enforcement and the criminal population, as `going to college'. This is because younger and less experienced offenders have the opportunity in prison to network with older and more experienced offenders who have already accumulated a great deal of criminal knowledge. Subsequently, a prison term of only a few years has the potential to advance an offender's skill level far beyond their original MO. Once released, such offenders may take their `education' and embark on criminal enterprises that before would have been beyond their ability. Criminals can also seek out knowledge directly, just like anyone else, without having to spend time with other, more experienced, criminals. They can learn from the things that they see or read, which include items ranging from those in the media to educational and technical materials. For example, a rapist may commit five different attacks in a single region. The attacks may go unconnected until DNA results come back and demonstrate that the rapes were more than likely committed by the same offender. If the media publishes a headline that reads `Serial rapist linked to five attacks by DNA!', the rapist may alter his MO behavior to prevent law enforcement from linking future cases. He may do so by making temporary changes, such as using a condom during any future rapes, or he may decide to make a more permanent change and undergo a vasectomy. Either way, the rapist may make a conscious attempt to prevent the transfer of a particular type of evidence, based on what he has learned from the media coverage of the case or other similar cases. However, MO behavior does not always evolve to become more competent as offenders progress through their criminal careers. Owing to a deteriorating mental state, the use of controlled substances, or increased confidence that law enforcement will not successfully apprehend them, offenders' MO behaviors can evolve over time to a less competent and less skillful level than when they first began. For example, the American serial murderer Theodore (Ted) Bundy,
who killed at least 30 victims across five states between 1973 and 1978, began his criminal career with a very competent, very well thought out MO. He was polite and friendly, extremely mobile and often approached his victims in some manner as to appear helpless or weak, and essentially nonthreatening. He sometimes accomplished this by presenting himself as a motorist who needed assistance with a disabled vehicle, and would often wear his arm in a sling. He also tended to select teenage females as victims, stalking them and selecting a disposal site for their bodies well in advance of committing an actual crime. But his MO deteriorated remarkably over time. After being incarcerated and then escaping on two separate occasions in Colorado, he made his way to Florida. He began to drink heavily, and he began to involve the bodies of his victims in rituals (signature behavior), including keeping the body for days at a time after death. There was also evidence that Bundy shampooed some of his victim's hair, and applied makeup to their corpses, rather than disposing of them immediately. In short, he began to leave more and more evidence behind, engaged in fewer precautionary acts, and became involved in more ritual behavior. His victim selection also changed; he chose his last victim, a 12-year-old female student from Florida, totally by virtue of her availability. This was a marked departure from his previous MO behavior of carefully stalking victims in advance and selecting victims who were in their late teens and early twenties. Understanding how MO can change over time, and the types of things that can influence those changes, has become an important part of using MO as an effective investigative tool.
Linkage Blindness The MO behavior demonstrated by a criminal can play an important role in law enforcement's linkage of related crimes. However, because MO behaviors can change over time, the tendency of law enforcement to rely solely upon an offender's MO for investigative strategy can lead to what has been termed `linkage blindness'; the failure to recognize a pattern that links one crime with another crime in a series of cases. Specifically, there are three very important factors that can act individually or in concert to cause linkage blindness: . the tendency for law enforcement to rely solely on MO behaviors like victim type, weapon selection and location type as a basis for case linkage; . the possibility that one predatory offender is operating in or near the same general area as another, confusing law enforcement efforts;
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. interpersonal or interagency conflicts, which can lead to communication breakdowns and a lack of information sharing.
Crime Linkage Systems: VICAP and VICLAS If you take a picture of a person who has committed a crime, then that person can be identified if he or she commits another crime later on. This fact was not lost on law enforcement as they began to incorporate photography into the criminal investigative process during the last half of the 1800s. As the sheer number of photographs of criminals began to grow, the need for a system of classification became apparent. The first classification systems adopted by law enforcement for their growing photographic databases were oriented towards MO behaviors. Photographs were sorted by virtue of the basic type of crime, and perhaps methods, used to commit the crime. Pickpockets who operated at racecourses went into one pile, while burglars who first `cased' the homes they intended to rob by posing as salesmen went into another. By the early 1900s, the contents of photographic databases had grown to substantial numbers and methods of classification had become more sophisticated and more competently crossreferenced. Criminal photographs were no longer simply classified by basic MO behaviors. Classification had evolved into advanced databases of criminal activity that were subclassified by factors such as method of entry into the crime scene, materials brought to commit the crime (i.e. flashlight, rope, lock picks, etc.), type of weapon used and physical description. Today, those at the forefront of developing law enforcement investigative techniques understand that there are a number of important, but often ignored, ways to link cases, apart from direct physical evidence and witness or victim statements. These include: . Modus operandi: similarities between actions taken by an offender that are necessary for the successful completion of the crime. . Signature: similarities between actions taken by an offender that are unnecessary for the successful completion of the crime; actions that suggest a psychological or emotional need. . Victimology: similarities or connections between victims. . Wound pattern analysis: a review of the autopsy or hospital protocols for a victim in an effort to find similarities between the nature and extent of injuries sustained during an attack. . Geographic region or location: offenses that have occurred in the same area, or the same type of area.
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There is a large amount of published information regarding the limitations of using MO behavior as a sole basis for linking solved and unsolved criminal cases, and the importance of understanding the concept of offender signature. However, even the most modern law enforcement case linkage initiatives tend to focus on understanding MO behavior alone. Violent Criminal Apprehension Program (VICAP)
The core of these ideas was brought into modern offender databasing by the late Pierce Brooks, an American law enforcement officer. Brooks joined the Los Angeles Police Department in 1948 and served in the vice, narcotics and homicide divisions. In 1958, Brooks was assigned two homicides that, although clearly unrelated, appeared to be the work of individuals who had killed before. He looked for resources to assist him in linking either of his homicides to any other cases in other parts of the country. There was nothing like that available on a national level. So Brooks used the only national information system available to him ± he went to the local library for hours at a time and sifted through newspapers from around the country in the hopes of finding stories that related cases with similar MO behavior. Brooks quickly came to realize that what was needed was a national database and information center that collected information on the MO of those killers that crossed jurisdictional boundaries. As early as 1958, he also knew that a computerized database of such information was the most effective way to make it nationally accessible. His technique of searching through library newspaper archives for related cases, born out of extreme necessity, was the basis for what was to become the Federal Bureau of Investigation's Violent Criminal Apprehension Program (VICAP). In 1983, Brooks testified before Congress about the possibility that unsolved murders around the country might be attributed to anonymous serial murderers. He explained that the only way to investigate the crimes and link the cases to apprehend these individuals was to put all of the information about each case into a computer database system that everyone in law enforcement could have access to. In 1984, with Brooks' help, the FBI's National Center for the Analysis of Violent Crime (NCAVC) was officially established. VICAP went online in 1985, with Brooks as the first program manager. Supervisory Special Agent Robert K. Ressler followed Brooks as the first agent program manager after Brooks terminated his FBI consultation. VICAP remains a nationwide data information center, specifically designed for collecting, sorting and analyzing solved and unsolved homicides, as
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well as missing persons cases where there is a strong possibility of foul play. According to the FBI, VICAP's mission remains to facilitate cooperation, communication and coordination between law enforcement agencies and provide support in their efforts to investigate, identify, track, apprehend and prosecute violent serial offenders. Law enforcement agencies can submit their unsolved and solved cases for comparison to those in the VICAP system via a handwritten 15-page report form. The VICAP Crime Analysis Report details administrative, victim and offender information, including MO, as well as information about location, forensic examinations and potentially related cases. The purpose of submitting the information is so that VICAP analysts can detect signature aspects and similar patterns of MO, and determine whether or not any cases in the current database may be linked. VICAP suffers greatly from underutilization by law enforcement. The primary complaint tends to be that the form is too long and too inconvenient to fill out in every case. End users of VICAP further complain that the database is too small, and that it should contain information regarding other types of interpersonal crime as well, such as rapes and sexual assaults. To augment the limited number of cases in the database, VICAP analysts have taken a page from the book of Pierce Brooks, and have populated it with information on solved and unsolved cases obtained from newspaper articles. Another weakness of VICAP, and similar statewide databases, is that analysts still predominately use MO behaviors to make initial case linkages. This essentially ignores the many other ways of avoiding linkage blindness that have proven more robust, such as offender signature. Although VICAP has not been significantly changed or modified since its inception in 1985, VICAP 2000 has been implemented, which expands the data base somewhat. Violent Crime Linkage Analysis System (VICLAS)
Following research into the FBI's VICAP system, the Canadian law enforcement community developed what was referred to as the Major Case File (MCF). It was Canada's first attempt to link homicide cases on a national level. Much like the VICAP report, investigators filled out their forms and submitted them to regional MCF analysts, who would manually input the data into the system. The MCF database was searchable by key words and phrases, and detectives would attempt to link offenses largely by MO behaviors. Despite the approximately 800 cases in the MCF database, no linkages had been made with the system as late as 1990.
In 1991, a Royal Canadian Mounted Police inspector, Ron McCay, who had recently received training through the FBI's criminal profiling fellowship program in Quantico, Virginia, helped to develop a new linkage system for Canada. It was to become the Violent Crime Linkage Analysis System (VICLAS). Its development was the result of analyzing not only the FBI's VICAP database but other statewide linkage systems in the United States as well. A far more ambitious and robust tool than the FBI's VICAP, VICLAS attempts to input information from the following sources: . all solved or unsolved homicides and attempted homicides; . solved and unsolved sexual assaults; . missing persons, where there is a strong possibility of foul play and the victim is still missing; . unidentified bodies, where the manner of death is known or suspected to be homicide; . all nonparental abductions and attempted abductions. An emphasis was also placed on the training and qualification of VICLAS analysts as an integral part of the system. Submissions still occur via a questionnaire that is filled out by an investigator and is sent to one of ten VICLAS centers servicing the various Canadian regions. However, there are numerous quality assurance reviews in place, and the VICLAS analysts may return forms to detectives if something is questioned. VICLAS analysts are trained to conduct structured queries of the system based on their own expertise, and arrive at potential linkages based on their own analysis of victimology, offender behavior, MO and forensic information. They are also trained to understand the concept of offender signature. Regardless of the results of their analysis, investigators in the field are charged with ultimately confirming or rejecting the links, based on the substance of their own investigation. The Canadian VICLAS initiative has become a popular model for law enforcement agencies involved in violent crime case linkage. Similar systems to VICLAS, though not directly connected, have been adopted in other countries, including Australia, Austria, Belgium, Holland and the United Kingdom. This speaks to the trend in the international law enforcement community to admit both that they have serial crime, and that an understanding of the relationship between MO and other elements that comprise criminal patterns is necessary to successfully link and investigate them. See also: Crime-scene Investigation and Examination: Scene Analysis and Reconstruction. Offender Signature.
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Further Reading Barbaree H, Laws D and Marshall W (1990) Handbook of Sexual Assault: Issues, Theories, and Treatment of the Offender. New York: Plenum Press. Bross H (1924) Criminal Investigation. (English Translation). London: Sweet and Maxwell. Burgess A and Hazelwood R (eds) (1995) Practical Aspects of Rape Investigation: A Multidisciplinary Approach. New York: CRC Press. Burgess A, Groth A and Holmstrom L (1978) Sexual Assault of Children and Adolescents. New York: Lexington. Burgess A, Douglas J and Ressler R (1988) Sexual Homicide: Patterns and Motives. New York: Lexington.
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Burgess A, Burgess A, Douglas J and Ressler R (1997) Crime Classification Manual. San Francisco: Jossey-Bass. Canter D and Alison L (1997) Criminal Detection and the Psychology of Crime. London: Ashgate. Egger S (1997) The Killers Among Us. Englewood Cliffs, NJ: Prentice Hall. Geberth V (1996) Practical Homicide Investigation, 3rd edn. New York: CRC Press. Groth AN (1979) Men Who Rape: The Psychology of the Offender. New York: Plenum Press. Holmes R and Holmes S (1996) Profiling Violent Crimes: An Investigative Tool, 2nd edn. Thousand Oaks, CA: Sage. O'Hara H (1970) Fundamentals of Criminal Investigation. Springfield: Charles C. Thomas. Turvey B (1999) Criminal Profiling: An Introduction to Behavioral Evidence Analysis. London: Academic Press.
Motor Vehicles see Accident Investigation: Airbag Related Injuries and Deaths; Driver Versus Passenger in Motor Vehicle Collisions; Motor Vehicle.
Murder see Crime-scene Investigation and Examination: Collection and Chain of Evidence; Contamination; Criminal Analysis; Fingerprints; Packaging; Preservation; Recording; Recovery of Human Remains; Scene Analysis and Reconstruction; Suspicious Deaths.
cal scale. Thus, the particle might be placed on a polished salt plate and extracted with droplets of ether delivered from a capillary pipette with the diameter of a hair. If the droplets are drawn off to the side with a tungsten needle, before they evaporate, a crescent-shaped droplet of the plasticizer will form there and the infrared spectrum can be quickly collected. The extracted particle might now be pressed to a thin film and its infrared spectrum obtained. Inorganic spectral peaks in the particle will be easier to interpret if it is transferred to a polarizing microscope. Many inorganic fillers and pigments, such as talc, calcite, quartz and titanium dioxide, can be readily identified on the basis of their optical properties. If necessary, to complete the interpretation, the particle can be washed free of index of refraction oil and mounted on a polished beryllium plate for EDS spectroscopy to confirm the elemental composition of the fillers. This hypothetical problem illustrates the advantages of an analytical approach, based on the utilization of both microchemistry and modern instrumentation, for the analysis or identification of microscopic items of evidence. See also: Analytical Techniques: Spectroscopy: Basic Principles. Serology: Blood Identification; Bloodstain Pattern Analysis. Analytical Techniques: Spectroscopic Techniques.
Further Reading Alimarin I and Petrikova N (1964) Inorganic Ultramicroanalysis. New York: Pergamon.
Amelink F (1962) Rapid Microchemical Identification Methods in Pharmacy and Toxicology. Amsterdam: Netherlands University Press. Benedetti-Pichler AA (1964) Identification of Materials via Physical Properties, Chemical Tests and Microscopy. New York: Springer. Chamot EM (1940) Handbook of Chemical Microscopy: Vol. II: Chemical Methods and Inorganic Qualitative Analysis. 2nd edn. New York: Wiley. Cheronis ND and Entrikin JB Semicro Qualitative Organic Analysis. The Systematic Identification of Organic Compounds, 2nd edn. New York: Interscience. Clarke EGC (1969, 1975) Isolation and Identification of Drugs in Pharmaceuticals, Body Fluids and PostMortem Material, vol. 1 (1969) and vol. 2 (1975). London: Pharmaceutical Press. Feigl F (1966) Spot Tests in Organic Analysis, 7th edn. Amsterdam: Elsevier. Feigl F (1972) Spot Tests in Inorganic Analysis, 6th edn. Amsterdam: Elsevier. Fulton CC (1969) Modern Microcrystal Tests for Drugs. The Identification of Organic Compounds by Microcrystalloscopic Chemistry. New York: Wiley-Interscience. Geilman W von (1954) Bilder zur Qualitativen Mikroanalyse Anorganischer Stoffe. Weinheim: Verlag Chemie. Jungreis E (1997) Spot Test Analysis Clinical, Environmental, Forensic and Geochemical Applications, 2nd edn. New York: Wiley-Interscience. Palenik SJ (1979) Microchemical reactions in particle identification. In: McCrone WC, Delly JG and Palenik SJ (eds) The Particle Atlas, 2nd edn, pp. 1174±1175. Ann Arbor: Ann Arbor Science. Schneider FL (1964) Qualitative Organic Microanalysis. Cognition and Recognition of Organic Compounds. New York: Academic Press.
Microscopy see Analytical Techniques: Microscopy. Microchemistry. Microtrace see Dust.
MODUS OPERANDI B E Turvey, Knowledge Solutions LLC, Watsonville, CA, USA Copyright # 2000 Academic Press doi:10.1006/rwfs.2000.0575
Introduction Modus operandi (MO) is a Latin term that means `a method of operating'. It is used by law enforcement agencies to refer to a criminal's pattern of behavior,
MODUS OPERANDI
or his or her way of committing crime. It is by understanding a criminal's MO behavior that most of those in law enforcement investigate and link criminal cases. This investigative approach has evolved from the use of criminal informants and highly experienced detectives, into the additional use of criminal database systems. The use of MO and criminal databases to link cases is but one of several important investigative methods available to law enforcement, and is separate from the concept of offender `signature'.
Definitions
Understanding Criminal Behavior
. to protect identity . to ensure success . to facilitate escape
Law enforcement has long held to the belief that understanding the methods criminals use to commit crime is the best way of searching for, and ultimately apprehending, them. This has traditionally required that detectives be a living encyclopedia of criminal cases and criminal behaviors, or that they learn to utilize the knowledge and experience of known criminals to inform their investigations. A strong belief in this way of approaching the process of criminal investigation was well demonstrated in France, in 1817, when a former convict named Eugene Vidocq, who had been working as a police spy, was assigned by the government to form a Brigade de SuÃreteÂ. He organized and led this group of detectives, mostly former criminals themselves, as it grew from a mere four to 28 in number. Vidocq and his detectives were paid according to the number of criminals that they apprehended. Within their first year, the group had made more than 750 arrests. This led some to believe that Vidocq and his detectives were a perfect solution to the local criminal problem; they understood how criminals operated, had insights into their habits and methods of operation, and were putting that knowledge to work for the good of the state. However, others suspected that Vidocq and his detectives committed many of the crimes themselves and then framed known criminals or undesirables in order to close out the cases. This suspicion was never proven, however, and Vidocq enjoys a largely favorable historical place as the first, and very successful, chief of the French SuÃrete Nationale. Whether or not Vidocq was a master detective or merely continued his criminal career through the SuÃreteÂ, a philosophy of criminal investigation emerged. To understand criminals, to develop competent investigative strategies, to link their crimes and to successfully apprehend them, detectives needed to understand the particular methods criminals used to commit their crimes. This is an investigative philosophy that survives on an international level, in one form or another, to the present day.
1117
Modus operandi has been defined as the actions taken by a criminal to perpetrate a crime successfully. A criminal's MO is comprised of learned behaviors that can evolve and develop, as they become more sophisticated and more confident. It is through analyzing MO behaviors that law enforcement agencies most commonly investigate and link crimes to a specific offender. A criminal's MO behavior is functional in nature. It generally serves any of three purposes for the offender:
General types of MO behaviors include, but are not limited to: . offense location selection (i.e. in a public park, on a school campus, or in a victim's residence, etc.); . involvement of a victim during a crime; . use of a weapon during a crime; . use of restraints to control the victim during a crime; . offender precautionary acts (i.e. wearing a mask, gloves, covering the victim's eyes during an attack, wearing a condom during a rape, forcing the victim to bathe after a sexual attack, etc.); . offender transportation to and from the crime scene (i.e. use of a bicycle, use of a motorized vehicle, walking, etc.). The criminal's MO, evidenced by MO behavior, is not the same thing as a criminal's motive, which is their reason for committing the crime. A criminal's motives are evidenced by signature behaviors that suggest overall signature aspects, or motivational aspects to the crime. Signature behaviors are those that satisfy the offender's emotional and psychological needs. They are often specialized behaviors, typically not necessary for the completion of the crime, and tend to show less evolution across offenses than MO behavior.
Influences on Modus Operandi A criminal's MO behavior is learned, and therefore dynamic and malleable. This is because MO behavior is affected by time, and can change as the criminal discovers that some of the things done during a crime are more effective than others. Criminals can subsequently recognize these effective actions, repeat them in future offenses, and become more skillful, refining their overall MO. However, behavior may also change due to a criminal's deteriorating mental state, due to
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the influence of controlled substances, and/or due to increased confidence that law enforcement will not successfully apprehend them. These things may cause a criminal's MO to become less skillful, less competent and more careless. Common ways that criminals can learn how to commit crime more skillfully are by gaining more experience, building confidence through success and/ or having more contact with the criminal justice system. Being arrested just once may teach an offender an invaluable lesson about how to avoid detection by law enforcement in the future. Further still, and with some great irony, a prison term in the United States is referred to by some, in both law enforcement and the criminal population, as `going to college'. This is because younger and less experienced offenders have the opportunity in prison to network with older and more experienced offenders who have already accumulated a great deal of criminal knowledge. Subsequently, a prison term of only a few years has the potential to advance an offender's skill level far beyond their original MO. Once released, such offenders may take their `education' and embark on criminal enterprises that before would have been beyond their ability. Criminals can also seek out knowledge directly, just like anyone else, without having to spend time with other, more experienced, criminals. They can learn from the things that they see or read, which include items ranging from those in the media to educational and technical materials. For example, a rapist may commit five different attacks in a single region. The attacks may go unconnected until DNA results come back and demonstrate that the rapes were more than likely committed by the same offender. If the media publishes a headline that reads `Serial rapist linked to five attacks by DNA!', the rapist may alter his MO behavior to prevent law enforcement from linking future cases. He may do so by making temporary changes, such as using a condom during any future rapes, or he may decide to make a more permanent change and undergo a vasectomy. Either way, the rapist may make a conscious attempt to prevent the transfer of a particular type of evidence, based on what he has learned from the media coverage of the case or other similar cases. However, MO behavior does not always evolve to become more competent as offenders progress through their criminal careers. Owing to a deteriorating mental state, the use of controlled substances, or increased confidence that law enforcement will not successfully apprehend them, offenders' MO behaviors can evolve over time to a less competent and less skillful level than when they first began. For example, the American serial murderer Theodore (Ted) Bundy,
who killed at least 30 victims across five states between 1973 and 1978, began his criminal career with a very competent, very well thought out MO. He was polite and friendly, extremely mobile and often approached his victims in some manner as to appear helpless or weak, and essentially nonthreatening. He sometimes accomplished this by presenting himself as a motorist who needed assistance with a disabled vehicle, and would often wear his arm in a sling. He also tended to select teenage females as victims, stalking them and selecting a disposal site for their bodies well in advance of committing an actual crime. But his MO deteriorated remarkably over time. After being incarcerated and then escaping on two separate occasions in Colorado, he made his way to Florida. He began to drink heavily, and he began to involve the bodies of his victims in rituals (signature behavior), including keeping the body for days at a time after death. There was also evidence that Bundy shampooed some of his victim's hair, and applied makeup to their corpses, rather than disposing of them immediately. In short, he began to leave more and more evidence behind, engaged in fewer precautionary acts, and became involved in more ritual behavior. His victim selection also changed; he chose his last victim, a 12-year-old female student from Florida, totally by virtue of her availability. This was a marked departure from his previous MO behavior of carefully stalking victims in advance and selecting victims who were in their late teens and early twenties. Understanding how MO can change over time, and the types of things that can influence those changes, has become an important part of using MO as an effective investigative tool.
Linkage Blindness The MO behavior demonstrated by a criminal can play an important role in law enforcement's linkage of related crimes. However, because MO behaviors can change over time, the tendency of law enforcement to rely solely upon an offender's MO for investigative strategy can lead to what has been termed `linkage blindness'; the failure to recognize a pattern that links one crime with another crime in a series of cases. Specifically, there are three very important factors that can act individually or in concert to cause linkage blindness: . the tendency for law enforcement to rely solely on MO behaviors like victim type, weapon selection and location type as a basis for case linkage; . the possibility that one predatory offender is operating in or near the same general area as another, confusing law enforcement efforts;
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. interpersonal or interagency conflicts, which can lead to communication breakdowns and a lack of information sharing.
Crime Linkage Systems: VICAP and VICLAS If you take a picture of a person who has committed a crime, then that person can be identified if he or she commits another crime later on. This fact was not lost on law enforcement as they began to incorporate photography into the criminal investigative process during the last half of the 1800s. As the sheer number of photographs of criminals began to grow, the need for a system of classification became apparent. The first classification systems adopted by law enforcement for their growing photographic databases were oriented towards MO behaviors. Photographs were sorted by virtue of the basic type of crime, and perhaps methods, used to commit the crime. Pickpockets who operated at racecourses went into one pile, while burglars who first `cased' the homes they intended to rob by posing as salesmen went into another. By the early 1900s, the contents of photographic databases had grown to substantial numbers and methods of classification had become more sophisticated and more competently crossreferenced. Criminal photographs were no longer simply classified by basic MO behaviors. Classification had evolved into advanced databases of criminal activity that were subclassified by factors such as method of entry into the crime scene, materials brought to commit the crime (i.e. flashlight, rope, lock picks, etc.), type of weapon used and physical description. Today, those at the forefront of developing law enforcement investigative techniques understand that there are a number of important, but often ignored, ways to link cases, apart from direct physical evidence and witness or victim statements. These include: . Modus operandi: similarities between actions taken by an offender that are necessary for the successful completion of the crime. . Signature: similarities between actions taken by an offender that are unnecessary for the successful completion of the crime; actions that suggest a psychological or emotional need. . Victimology: similarities or connections between victims. . Wound pattern analysis: a review of the autopsy or hospital protocols for a victim in an effort to find similarities between the nature and extent of injuries sustained during an attack. . Geographic region or location: offenses that have occurred in the same area, or the same type of area.
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There is a large amount of published information regarding the limitations of using MO behavior as a sole basis for linking solved and unsolved criminal cases, and the importance of understanding the concept of offender signature. However, even the most modern law enforcement case linkage initiatives tend to focus on understanding MO behavior alone. Violent Criminal Apprehension Program (VICAP)
The core of these ideas was brought into modern offender databasing by the late Pierce Brooks, an American law enforcement officer. Brooks joined the Los Angeles Police Department in 1948 and served in the vice, narcotics and homicide divisions. In 1958, Brooks was assigned two homicides that, although clearly unrelated, appeared to be the work of individuals who had killed before. He looked for resources to assist him in linking either of his homicides to any other cases in other parts of the country. There was nothing like that available on a national level. So Brooks used the only national information system available to him ± he went to the local library for hours at a time and sifted through newspapers from around the country in the hopes of finding stories that related cases with similar MO behavior. Brooks quickly came to realize that what was needed was a national database and information center that collected information on the MO of those killers that crossed jurisdictional boundaries. As early as 1958, he also knew that a computerized database of such information was the most effective way to make it nationally accessible. His technique of searching through library newspaper archives for related cases, born out of extreme necessity, was the basis for what was to become the Federal Bureau of Investigation's Violent Criminal Apprehension Program (VICAP). In 1983, Brooks testified before Congress about the possibility that unsolved murders around the country might be attributed to anonymous serial murderers. He explained that the only way to investigate the crimes and link the cases to apprehend these individuals was to put all of the information about each case into a computer database system that everyone in law enforcement could have access to. In 1984, with Brooks' help, the FBI's National Center for the Analysis of Violent Crime (NCAVC) was officially established. VICAP went online in 1985, with Brooks as the first program manager. Supervisory Special Agent Robert K. Ressler followed Brooks as the first agent program manager after Brooks terminated his FBI consultation. VICAP remains a nationwide data information center, specifically designed for collecting, sorting and analyzing solved and unsolved homicides, as
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well as missing persons cases where there is a strong possibility of foul play. According to the FBI, VICAP's mission remains to facilitate cooperation, communication and coordination between law enforcement agencies and provide support in their efforts to investigate, identify, track, apprehend and prosecute violent serial offenders. Law enforcement agencies can submit their unsolved and solved cases for comparison to those in the VICAP system via a handwritten 15-page report form. The VICAP Crime Analysis Report details administrative, victim and offender information, including MO, as well as information about location, forensic examinations and potentially related cases. The purpose of submitting the information is so that VICAP analysts can detect signature aspects and similar patterns of MO, and determine whether or not any cases in the current database may be linked. VICAP suffers greatly from underutilization by law enforcement. The primary complaint tends to be that the form is too long and too inconvenient to fill out in every case. End users of VICAP further complain that the database is too small, and that it should contain information regarding other types of interpersonal crime as well, such as rapes and sexual assaults. To augment the limited number of cases in the database, VICAP analysts have taken a page from the book of Pierce Brooks, and have populated it with information on solved and unsolved cases obtained from newspaper articles. Another weakness of VICAP, and similar statewide databases, is that analysts still predominately use MO behaviors to make initial case linkages. This essentially ignores the many other ways of avoiding linkage blindness that have proven more robust, such as offender signature. Although VICAP has not been significantly changed or modified since its inception in 1985, VICAP 2000 has been implemented, which expands the data base somewhat. Violent Crime Linkage Analysis System (VICLAS)
Following research into the FBI's VICAP system, the Canadian law enforcement community developed what was referred to as the Major Case File (MCF). It was Canada's first attempt to link homicide cases on a national level. Much like the VICAP report, investigators filled out their forms and submitted them to regional MCF analysts, who would manually input the data into the system. The MCF database was searchable by key words and phrases, and detectives would attempt to link offenses largely by MO behaviors. Despite the approximately 800 cases in the MCF database, no linkages had been made with the system as late as 1990.
In 1991, a Royal Canadian Mounted Police inspector, Ron McCay, who had recently received training through the FBI's criminal profiling fellowship program in Quantico, Virginia, helped to develop a new linkage system for Canada. It was to become the Violent Crime Linkage Analysis System (VICLAS). Its development was the result of analyzing not only the FBI's VICAP database but other statewide linkage systems in the United States as well. A far more ambitious and robust tool than the FBI's VICAP, VICLAS attempts to input information from the following sources: . all solved or unsolved homicides and attempted homicides; . solved and unsolved sexual assaults; . missing persons, where there is a strong possibility of foul play and the victim is still missing; . unidentified bodies, where the manner of death is known or suspected to be homicide; . all nonparental abductions and attempted abductions. An emphasis was also placed on the training and qualification of VICLAS analysts as an integral part of the system. Submissions still occur via a questionnaire that is filled out by an investigator and is sent to one of ten VICLAS centers servicing the various Canadian regions. However, there are numerous quality assurance reviews in place, and the VICLAS analysts may return forms to detectives if something is questioned. VICLAS analysts are trained to conduct structured queries of the system based on their own expertise, and arrive at potential linkages based on their own analysis of victimology, offender behavior, MO and forensic information. They are also trained to understand the concept of offender signature. Regardless of the results of their analysis, investigators in the field are charged with ultimately confirming or rejecting the links, based on the substance of their own investigation. The Canadian VICLAS initiative has become a popular model for law enforcement agencies involved in violent crime case linkage. Similar systems to VICLAS, though not directly connected, have been adopted in other countries, including Australia, Austria, Belgium, Holland and the United Kingdom. This speaks to the trend in the international law enforcement community to admit both that they have serial crime, and that an understanding of the relationship between MO and other elements that comprise criminal patterns is necessary to successfully link and investigate them. See also: Crime-scene Investigation and Examination: Scene Analysis and Reconstruction. Offender Signature.
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Further Reading Barbaree H, Laws D and Marshall W (1990) Handbook of Sexual Assault: Issues, Theories, and Treatment of the Offender. New York: Plenum Press. Bross H (1924) Criminal Investigation. (English Translation). London: Sweet and Maxwell. Burgess A and Hazelwood R (eds) (1995) Practical Aspects of Rape Investigation: A Multidisciplinary Approach. New York: CRC Press. Burgess A, Groth A and Holmstrom L (1978) Sexual Assault of Children and Adolescents. New York: Lexington. Burgess A, Douglas J and Ressler R (1988) Sexual Homicide: Patterns and Motives. New York: Lexington.
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Burgess A, Burgess A, Douglas J and Ressler R (1997) Crime Classification Manual. San Francisco: Jossey-Bass. Canter D and Alison L (1997) Criminal Detection and the Psychology of Crime. London: Ashgate. Egger S (1997) The Killers Among Us. Englewood Cliffs, NJ: Prentice Hall. Geberth V (1996) Practical Homicide Investigation, 3rd edn. New York: CRC Press. Groth AN (1979) Men Who Rape: The Psychology of the Offender. New York: Plenum Press. Holmes R and Holmes S (1996) Profiling Violent Crimes: An Investigative Tool, 2nd edn. Thousand Oaks, CA: Sage. O'Hara H (1970) Fundamentals of Criminal Investigation. Springfield: Charles C. Thomas. Turvey B (1999) Criminal Profiling: An Introduction to Behavioral Evidence Analysis. London: Academic Press.
Motor Vehicles see Accident Investigation: Airbag Related Injuries and Deaths; Driver Versus Passenger in Motor Vehicle Collisions; Motor Vehicle.
Murder see Crime-scene Investigation and Examination: Collection and Chain of Evidence; Contamination; Criminal Analysis; Fingerprints; Packaging; Preservation; Recording; Recovery of Human Remains; Scene Analysis and Reconstruction; Suspicious Deaths.