Internet Crime Archives Serial killers tend to be white, heterosexual, males in their twenties and thirties who are loners with low self-esteem. Their methodical rampages are almost always sexually motivated. Their killings are usually part of an elaborate sexual fantasy that builds to a climax at the moment of their murderous outburst. Serial killers generally murder strangers with cooling off periods between each crime. Many enjoy cannibalism, necrophilia and keep trophy-like body parts as mementos of their work.
Serial killers are sadistic in nature.
Sometimes they like to return to grave sites and crime scenes to fantasize about previous kills. Many killers like to insert themselves in the investigations of their crimes and some like to taunt the police with letters or carefully placed pieces of evidence at the crime scene.