What is a serial killer?
Defining serial killers precisely can be difficult, so it is often easier to start by saying what they are not:
- Serial killers do not usually kill people they know – they are ‘stranger-killers’
- Serial killers usually kill only one or two people at a time – they are not spree killers like those who attack schools or churches in the USA
- They do not kill for political or military reasons
What makes serial killers do what they do is still uncertain, and can differ, but most suffer from some form of mental illness. They often pick a particular group of people (prostitutes, particular races, even hair colour). Most serial killers are men, and many appear to be sado-sexual killers.
Serial killers do kill repeatedly over an extended period, although the regularity of their killings may vary. They usually keep killing until they are caught, they die or they kill themselves.
Killing is a compulsion, not a choice
They have a compulsion to kill that drives them on, and often they put a lot of effort into planning their killings and selecting their victims. And for many of them, the murder itself is the reason for killing.
Most sexual killers kill alone and kill single victims. Despite stereotypes in movies and TV shows, serial killers are not desperate to be caught. They are driven to keep killing, and working alone is a way to protect themselves.
But there are also killer couples (like Myra Handley and Ian Brady), where they are lovers and (usually) the man is the leader: but is some couples, the woman is the driving force. There are also couples who kill together, but are not lovers: usually there is a power relationship there to hold the couple together. They have been some gay couples. Serial killer gangs are rare, but not unknown.
No connection to their victims
Serial killers were difficult to find in the early days of detection, because very few serial killers murder people they have connections with – they usually kill strangers.
The main exception to this has been the mothers killing their children or people killing a series of partners (usually in insurance fraud, a crime that was very common in the first half of the 20th century, but which modern forensic science has made very rare.
But in more recent times, the medical killers, driven by their need for power over patients, have become more common. There have probably always been killer doctors and nurses, but again modern forensic science has made the cases detectable, as they usually involve poison.
Travel is also much easier now, and so serial killers can kill across wide areas, even continent-wide.
Excessive violence
It is very common for serial killers use excessive violence, either in the murder itself or around it. Torture before killing or mutilation after death are both common.
This is often because the killers get sexual pleasure from the act of killing, and sadism for sexual pleasure drives many to their extremes.