In California, you now actually have to participate in a murder to be charged with murder.

Over the weekend, Gov. Jerry Brown signed S.B. 1437, a bill that significantly restricts the application of what's known as the "felony murder rule." Under this rule, accomplices could be charged with murder whenever somebody is killed in the commission of a felony crime, even when they played no role in these deaths, sometimes even if they weren't at the scene of the murder.

In short, there are people in prison for murder who did not commit "murder" under any logical definition of the word. The Los Angeles Times reports that 72 percent of women behing bars in California for felony murder did not, in fact, commit the killing for which they're now serving life sentences.

Take the case of Bobby Garcia. He and some friends robbed a man for gas money when he was in high school. Somebody stabbed the man to death. When the man was stabbed, Garcia says he was waiting in the car to flee the robbery. But under California law, that didn't matter: He was charged not just for his role in the robbery but with murder, as though he had committed the slaying himself. He wound up serving 21 years. Now a free man, he's been lobbying for these changes.

Under S.B. 1437, co-sponsored by a Democrat and a Republican in the state Senate, a person can only be convicted of felony murder if he or she actually participated in the killing, acted with intent to assist the killer, or was a "major participant" in the underlying felony and acted "with reckless indifference to human life."

The bill also allows for those who have been previously convicted for these felonies to get those convictions tossed and be resentenced. This may affect between 400 and 800 people currently serving prison time, according to the Sacramento Bee.

Those numbers might seem low, given that more than 120,000 people are serving time in state prisons in California. But keep in mind the prospect of a felony murder life sentence has also been a tool to browbeat defendants into plea deals. That's what happened with Garcia. Changing this rule means one less way for prosecutors to intimidate defendants.

Unless one of their buddies killed a cop. S.B. 1437 has one big exception: It doesn't apply when the victim is a police officer. If one of your partners in crime panics kills a cop, you're all getting charged with murder.