This is in relation to German law which, according to the German Association of Lawyers, the Nazis decided that a murderer was someone who killed "treacherously" or "sneakily" - "heimtueckisch" is the word in the law and it remains there today.
"The Nazi law favoured - and still favours - the strong who murder the weak, Koenig argues."
Dr Stefan Koenig, a Berlin defence lawyer who chairs the Association of Lawyers' penal committee, says the Nazis defined murder in the light of their belief that some people were inherently weak-minded. It was about defining a murderer as someone treacherous rather than looking at the circumstances of each individual crime.
East Germany had a different law, closer to the idea in the United States, UK and many other countries, that murder requires an intention to kill or cause serious injury. But with the unification of Germany in 1990, the law of West Germany became the law of the land.
"In the penal code concerning murder, somebody is guilty of murder but not manslaughter if he abuses the victim's defencelessness, abusing the fact that the victim is not aware of any attack," he says.