A mutant of duress involves hostage taking, where a person is forced to commit a criminal act under the threat, say, that their family member or close associate will be immediately killed should they refuse (commonly known as a Tiger kidnapping). This has been raised in some cases of ransom, where a person commits theft or embezzlement under orders from a kidnapper in order to secure a family member's life and freedom. However, duress is not a complete defense to all crimes. For example, the general rule, both at common law and today, is that duress is never a defense to murder; that is, one is never justified in killing another innocent person even if one's own life has been threatened, although this part may be questioned when multiple people are threatened with death if the defendant does not kill a single or fewer people than threatened (such a situation is similar to the trolley problem). A counterpart may be found in a English law, where in R_v_Dudley_and_Stephens involved a case of one man being killed to save two lives - no duress defense was available and they were convicted.