California Governor Jerry Brown on Monday signed into law an anti-bullying measure named after gay student Seth Walsh.

Walsh is the 13-year-old boy who hanged himself after he was endlessly harassed by classmates who perceived him to be gay. He died 9 days after his mother Wendy Walsh found him hanging from a plum tree in their backyard. A federal investigation concluded that Tehachapi Unified School District failed to properly respond to the teen's ongoing harassment.

The legislation was introduced by openly gay Assemblyman Tom Ammiano, a Democrat from San Francisco, and cleared the Assembly on June 1 on a 52-26 vote.

Senators approved the legislation with a 24 to 14 vote on September 7.

The new law mandates that schools post anti-bullying policies throughout campuses, provide complaint forms on their websites and give schools a timeline to investigate and resolve complaints.

Anti-gay rights organizations in the state have already launched a petition drive to repeal SB 48, a law that mandates schools include the historical contributions of LGBT people in their lesson plans, but have remained silent on Seth's Law.

(Related: Wendy Walsh talks about her son's suicide.)