 Not much is known about Chill except that he is, in most versions of "Batman", a petty mugger who kills Bruce's parents Thomas and Martha while trying to take their money and jewelry.When he demands Martha's necklace, Thomas moves to protect his wife and Chill panics and shoots him; he then kills Martha when she screams for help (in later versions up to the 1970s, Martha dies from a heart attack brought on from the shock of seeing her husband murdered).Chill runs away when Bruce begins crying and calling for help — but not before the boy memorizes his features.