Question: Does a serial killer basically use the same "tools" in his "work"? (I know there's a difference between MO and Signature, but I can never figure it out).
Evelezrn, Vernon Geberth prolly explains the difference between MO & Signature much better than I could and shares a couple of examples to distinguish between the two.
http://www.practicalhomicide.com/Research/CriminalInvestigativeAnalysisJuly2015.htm
Modus Operandi and Signature
In addition to victimology and presentation of the victim in the crime scene the investigator must understand the significance of M.O. and Signature especially in sex-related incidents.
Modus Operandi is a learned behavior that tends to change as offenders gain experience and/or build confidence in their crimes. Some reasons for a change in an offender M.O. could be attributed to experience, maturity, education, incarceration/jail time, criminal versatility, and/or technology.
Some examples of modus operandi are an offender who brings a weapon, uses a con, the times of crime, The days of the week, intelligence gathering (Stalking), methods of control of victim, use of the victims vehicle, and the location of crime scenes ((Inside or Outside).
Many serial offenders target prostitutes and their M.O. is simply to pose as a John in order to get their victims away from an area and into a comfort zone where they can act out their sexual fantasies. Richard Cottingham, who was a serial killer operating in both New York City Bergen County, New Jersey targeted prostitutes. In some cases he would pick-up women in a New York City bar and slips a date-rape drug into their drinks. He would then take them to a New Jersey hotel where he would sexually assault and torture them. In some cases he left them nude and battered with burns on their breasts. In other incidents if he felt they could identify him he would kill them and leave their bodies in hotels in New York City and New Jersey. He was a classic Signature Killer and all of crimes were linked through his signature behavior.
Other sexual offenders establish a casual relationship with a prospective victim that eventually allows them access to a victims home. Once the offender was in the victims residence he would sexually attack and kill them to prevent identification.
I consulted on one particular case where the offender had started out as a Cat Burglar who entered victims homes in the middle of the night to steal their valuables. On one particular occasion he encountered a young women living alone. In a classic example of an opportunistic crime, he sexually attacked and raped her. He then began to stalk and target women who lived alone. The burglary and thefts became secondary to his primary intention, which was to rape and sodomize his victims.
He was caught in one young womans home with his rape kit before he could assault her. He was charged with Burglary and Attempted Rape. He pled guilty to the Burglary and was paroled. Within two weeks of his parole he became a serial killer. He raped and sodomized four women during his home invasions to satisfy his lust and then killed them to prevent them from identifying him or ever being able to testify against him in court. .
He was also classic Signature Killer and all of crimes were linked by his specific type of binding the sexual activity, his DNA and his modus operandi.
The Signature Aspect of a violent sexual offender is a unique and integral part of the offenders behavior, which refers to the psychodynamics of the event. The psychodynamics are the mental and emotional processes underlying human behavior and its motivations.
The Signature aspect is the end result of a number of biological, psychological and psychosocial factors that have combined to influence how an individual seeks sexual satisfaction or is able to sexually perform. The nucleus of the Signature element begins at an early age and is reinforced through repetitive fantasy, masturbatory activity and situational acting-out of these themes in various non-criminal scenarios.
Sexual fantasies play a major role in everyones sexual behavior. It is the drive factor for sexual expression. The sexual offender and other individuals, who are aroused with thoughts and fantasies of sexual aggression, reinforce their beliefs through repetition illustrated by the use of sadistic *advertiser censored* and fantasy drawings. These serve as a form stimulus and excitement, a rehearsal before actually committing the offense or a mental re-creation of an actual event and represent the Signature component.
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