State lawmakers on Thursday passed a bill that would make California the first state to define when "yes means yes" while investigating sexual assaults on college campuses.

The Senate unanimously passed SB967 as states and universities across the U.S. face pressure to change how they handle rape allegations. The bill now goes to Gov. Jerry Brown, who has not indicated his stance on the bill.

Sen. Kevin de Leon, D-Los Angeles, said his bill would begin a shift in how California campuses prevent and investigate sexual assault.

Rather than using the refrain "no means no," the definition of consent under the bill requires "an affirmative, conscious and voluntary agreement to engage in sexual activity." Earlier versions of the bill had similar language.

Silence or lack of resistance does not constitute consent. The legislation says it's also not consent if the person is drunk, drugged, unconscious or asleep.

Lawmakers say consent can be nonverbal, and universities with similar policies have outlined examples as maybe a nod of the head or moving in closer to the person.

Advocates for victims of sexual assault supported the change as one that will provide consistency across campuses and challenge the notion that victims must have resisted assault in order to have valid complaints.

Some critics say the legislation is overreaching and sends universities into murky, unfamiliar legal waters.

Gordon Finley, an adviser to the National Coalition for Men, wrote an editorial asking Brown not to sign the bill. He argued that "this campus rape crusade bill" presumes the guilt of the accused.

The bill passed the state Assembly on Monday by a 52-16 vote. Some Republicans in that house questioned if statewide legislation is an appropriate venue to define consent.

There was no opposition from Senate Republicans.

The bill would apply to all California post-secondary schools, public and private, that receive state money for student financial aid. The California State University and University of California systems are backing the legislation after adopting similar consent standards this year.

The bill also requires colleges and universities to adopt "victim-centered" sexual-assault response policies and implement comprehensive programs to prevent assault.

In January, President Barack Obama vowed to make the issue a priority. He announced a task force chaired by Vice President Joe Biden that created a website providing tips for filing complaints, www.notalone.gov, and issued a report in May naming 55 colleges and universities across the country facing investigation for their responses to sexual abuse and violence. The University of California, Berkeley was included on the list.

The White House Council on Women and Girls reported (PDF) the staggering fact that nearly 1 in 5 college women is sexually assaulted by the time she graduates, with just 12 percent of them reporting the assaults — a much lower rate than the estimated 40 percent of assaults that are reported by the general population, according to the Department of Justice.

In addition, students from a number of colleges and universities — including the University of California at Berkeley and the University of Southern California, Dartmouth College, Columbia University, Harvard College, Occidental College, Swarthmore College — have filed complaints in the last year that their schools violated the Clery Act and Title IX of the Civil Rights Act by mishandling their sexual assault cases.

Al Jazeera and The Associated Press