In the Vancouver Sun recently, I saw this statement: “A serial killer is defined as someone who commits more than three murders over a period that spans more than one month. For the most part, serial killers commit murder for some sort of psychological benefit.”

 I’ve seen similar definitions in many other media reports, despite the FBI’s change in 2005 to a minimum of two murders with no reference to motive or timeframe. This is not surprising, considering the haphazard history of the term.

The phrase, “serial killer,” was first used in a book, The Complete Detective, in 1950, while serienmörder was coined in 1931 in Germany in reference to Peter Kürten.

However, it’s generally believed that in 1976, with the “Son of Sam” case in New York City, Special Agent Robert Ressler initiated its use for law enforcement in the U.S. He and his colleagues in the FBI’s budding Behavioral Science Unit (now Behavioral Analysis Unit) were often called into cases involving multiple murders, many of which were comprised of distinct but related events. Thus, “serial killer” became common parlance for a specific type of multiple murder incident.

The earliest editions of the FBI’s official Crime Classification Manual indicate that to be defined as a serial killer, there must be at least three different murder events at three different locations, with a cooling off period between events. (So, that’s like the Vancouver Sun’s approach.)

Yet during this same period, the National Institute of Justice and some prominent criminologists allowed for two victims for a serial killer. In addition, some killers brought their victims to the same location at different times, so having three or more distinct locations was not a necessary condition.

As more research was devoted to serial murder, some experts reserved the definition exclusively for sexually compelled offenders, while others included nonsexual goals such as financial gain. Some accepted violent dictators as serial killers, and as I said in an earlier blog, there has been plenty of confusion about how to differentiate serial murder from incidents involving spree or mass murder.

In general (before the FBI dropped the “spree killer” category eight years ago), a mass murderer kills at least four people in a single incident and in a specific location, while a spree killer tends to keep killing over a period of days or weeks, and at different locales, but sans that key “cooling off” period. Or so some criminologists have defined these terms.

And then there are the mixed types with which to contend. For example, on September 22, 1980, a 14-year-old African American boy was shot in Buffalo, New York. There were two similar murders the following day, with a fourth incident in nearby Niagara Falls. Witnesses saw a young white man with dark hair running away. An investigation produced a dropped .22-caliber shell casing, so he was dubbed the “.22-caliber Killer.” 

Switching weapons no less than three times, he stopped for a while and then emerged again to kill several more times. He used a screwdriver on one man and a hammer on another. He also removed the hearts of two victims.

Several weeks passed. Then another series began, this time in Manhattan. In just a few hours, a knife-wielding man attacked five black males and one Hispanic man, killing four. Then two more black men were stabbed to death back in Buffalo.

Investigators were stymied until a 25-year-old soldier at Fort Benning named Joseph Christopher admitted to a nurse that he’d killed some black people in New York. Forensic evidence was found among his effects, and when he confessed to law enforcement, he said, “It was something I had to do.” Christopher was convicted and sentenced to life in prison.

He is a multiple murderer. Some call him a serial killer, and he was. Some call him a spree killer, and he was also that. His case demonstrates the difficulty of placing offenders in distinct categories, because his methods and motives fit both.

Dennis Rader (“B.T.K.”) began with a family slaughter of four, which made him a mass murderer. He then killed several single women over a span of several decades. Today, no one thinks of him as a mass murderer, although he is. He is considered a serial killer.

It’s no wonder there’s confusion about the definition. I use the FBI’s definition, myself, but I’ve had people write to me at this blog to tell me how wrong I am, because “everyone knows” that the minimum number of victims is three…or four…or five. There’s no consensus even among my critics. I wonder if we’ll all ever get on the same page.

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