The term “true crime” is not a legal term because in law a crime is a crime so long as a specific law declares certain act or omission as such. A true crime usually refers to serious offences such as robbery, burglary, murder and rape which virtually all societies define as criminal.
There are other moral transgressions such as adultery, bhang-smoking, homosexuality between consenting adults and abortion in respect of which controversy rages on whether they are true crimes or matters for personal morality.