If this were a film, one would suspect it to be a comedy; as it is a documentary, most crime buffs will have guessed correctly that it is about forensic science. It begins on a lighter note, but soon the viewer finds himself surrounded by insects extracted from corpses and discussions about DNA.
A number of notorious cases are covered; there is archive footage of the Sussex workshop where acid bath murderer Haigh disposed of his victims, a word or two from the ghoulish Jeffrey Dahmer, and fittingly the programme finishes with Britain's most prolific serial killer, Dr Harold Shipman.
At the end we are told the best way to commit a perfect murder is for a budding serial killer to stop after his first victim. Actually, the best way is to wear a badge, but that is a subject for a different type of documentary.