Policymakers in California have voted unanimously for a new bill that prevents perpetrators of sexual assault from being sentenced to probation, inspired by the "slap on the wrist" punishment of Stanford rapist Brock Turner. The bill, from state legislators Bill Dodd, Evan Low and Senator Jerry Hill, who worked with Santa Clara DA Jeff Rosen on the proposal, ensures anyone convicted of sexual assault must serve time in prison – something that previously only applied to perpetrators who used force on their victims.

The new bill would ensure a rapist who assaulted an unconscious victim, as in the case of Stanford's Brock Turner, would face the same penalty as those who assaulted their victims while they were awake.

"Sexually assaulting an unconscious or intoxicated victim is a terrible crime and our laws need to reflect that. Letting felons convicted of such crimes get off with probation discourages other survivors from coming forward and sends the message that raping incapacitated victims is no big deal," said assembly member Dodd.

"This bill is about more than sentencing, it's about supporting victims and changing the culture on our college campuses to help prevent future crimes."

Turner's case attracted a great deal of attention after he was sentenced to six months in prison and three years' probation for sexually assaulting an unconscious woman at a party at Stanford University's campus, in a sentence widely criticised for its leniency.

"Rape is rape, and rapists like Brock Turner shouldn't be let off with a slap on the wrist," said assembly member Low. "Judge (Aaron) Persky's ruling was unjustifiable and morally wrong, however, under current state law it was within his discretion. Current law actually incentivises rapists to get their victims intoxicated before assaulting them. While we can't go back and change what happened, we can make sure it never happens again."

Rosen added that the letter written by the victim of Turner's assault had helped shape the bill and make the state safer. "We thank Evan Low, Bill Dodd, Jerry Hill, and Governor Brown for helping make California safer for women today. Mostly, we thank Emily Doe for her courageous letter. It gave all of us the inspiration to make sure the next Brock Turner either leaves the next Emily Doe alone, or the next Brock Turner goes to prison," he added.