How to Catch a Serial Killer

Crime shows and police procedure dramas (like Criminal Minds and Law and Order) that flood our television experience give the appearance that serial killers are caught by the use of criminal profiling and sophisticated forensic tools such as fingerprint analysis, DNA technology, digital tracking, blood spatter analysis, ballistic comparisons and many more. But how much of it is real? Are criminal profiling and forensic science really responsible for capturing most serial killers?

White, Lester, Gentile and Rosenbleeth (2011) investigates this question by studying 200 serial killers. They found that although forensic evidence was often key in getting a conviction, no serial killer was captured by the use of forensic evidence or criminal profiling. Instead, the reason serial killers were caught was traditional police work and communication with the public.

What is a serial killer?

For the purpose of this paper, a serial killer is defined as:

a person who has killed at least three people at different locations with a ‘cooling off’ period between the killings”

Special accommodations were made for a minority of repeated killers who killed at home (Gacy and Dahmer) or at a hospital (angel of death). This is different from a mass killer or mass shooter who, depending on definition, kills 3-4 people in the same general location and time.

What was the sample size and how was the sample selected?

A total of 200 serial killers were included in this study. Facts about the serial killers in the sample was taken from “newspaper reports, true crime books, and encyclopedias” and then “referenced with other sources”. The identity of these “other sources” are left unspecified.

What role did criminal profiling / forensic science play in catching serial killers?

None of the serial killers were identified or captured by criminal profiling or forensic science alone. Not a single one. The authors write:

Interestingly, not one serial killer in the present study, albeit limited to 200 subjects, was captured by forensic evidence alone, without the help of the public or the investigative acumen of the police by interviewing the public.

It should be noted, however, that forensic science such as DNA evidence, often played a crucial role in attaining a conviction against the serial killers in this sample. Thus, in contrast to police procedural dramas such as Criminal Minds, criminal profiling and forensic evidence plays a minor role in identifying and finding serial killers.

How are serial killers caught?

So if criminal profiling and/or forensic evidence does not play a leading role in identifying and capturing serial killers, how are they captured?

The study found 12 distinct categories and here they are ordered from the least common to the most common:

• Victim released (1%): a victim is released by the serial killer e. g. Bobby Joe Long let a woman go who later told police how the car looked and where he had held her.
• Serial killer death (1.5%): the victim kills the serial killer during the crime e. g. Wayne Nance was killed by the husband of the couple we was about to kill.
• Turned themselves over (2%): serial killers who turned themselves over to the police and confessed to their crimes e. g. Edmund Kemper.
• Was seen with victims before murder (2%): witnesses identified the serial killer e. g. Antone Costa was seen with his victims and even drove the car of one of them victim.
• Sent stuff to the police or media (2.5%): sending storage media or letters e. g. BTK killer mailed a storage device to local media.
• Caught red hand (5.5%): killers who were caught while killing or about to kill a victim e. g. Jeanne Weber was caught by police while trying to strange a young man.
• Victim survived (7.5%): the serial killer left victims alive e. g. Harvey Carignan got sloppy and left several victims alive who could later identify him.
• Victim escaping (8%): the serial killer was unable to hold a victim who escaped in various ways e. g. Dahmer’s last target fled after struggle, waved down some cops and told them what happened to him.
• Linked to the crime scene (16.5%): Green River killer was linked to secondary crime scenes as he often bought sex from prostitutes near the sites were he abducted his victims.
• Linked to victims, other than via eyewitnesses (16.5%): the serial killer gets linked to the victims by routes other than direct eyewitnesses e. g. one victim of John Wayne Gacy told his mom and others that he was going to a carpenter called Gacy to try to get a job.
• Arrested for something else (16.5%): the serial killers get arrested for another related or unrelated crime e. g. Ted Bundy was arrested for car theft.
• Police tipped off by someone close to them (20.5%): the serial killer gets caught because someone who knew the serial killer, such as family, friends or associate contacted the police e. g. family of the Unabomber Ted Kaczynski recognized hand writing and turned him in.

Conclusion:

There are two major conclusions from this paper:

1. Forensic science and criminal profiling does not play any particular role in capturing serial killers. Instead, it is traditional police work and a productive relationship with the public that plays a massive role in the capturing of serial killers. The paper states that 71.5% of all serial killers in the sample was captures as a result of “direct observations, descriptions, and other information provided by surviving victims, direct witnesses, and even family members of serial killers”.

2. The way the capture of serial killers is being portrayed in police television programs, such as Criminal Minds, is scientifically inaccurate.