What is "rodef"

A rodef ( Hebrew רודף, lit. "pursuer"; pl. רודפים, rodfim), in traditional Jewish law, is one who is "pursuing" another to murder him or her. According to Jewish law, such a person must be killed by any bystander after being warned to stop and refusing. The source for this law is the Tractate Sanhedrin in the Babylonian Talmud, page 73a, which begins:

And these are the ones whom one must save even with their lives [i.e., killing the wrongdoer]: one who pursues his fellow to kill him [rodef achar chavero le-horgo], and after a male or a bethrothed maiden [to rape them]; but one who pursues an animal, or desecrates the Sabbath, or commits idolatry are not saved with their lives.

This law, the din rodef ("law of the pursuer"), is significant as one of the few provisions in Jewish law permitting extrajudicial killings.

The allowance to kill the rodef does not apply, however, in a case where lesser means would prevent the innocent's murder. Furthermore, according to the Rambam, killing a rodef who may have been stopped by lesser means constitutes murder, though the punishment for a murderer in this case is not dealt out by Beit din.