California has become the first American state to introduce a law allowing family members to get a court order to impound firearms if they believe a close relative might commit a gun crime.
The bill was sponsored after the police said they were unable to confiscate the weapons of a man who killed six people in May, despite warnings about over his mental state, the BBC reports.
It was introduced on the same day the mayor of a California suburb was fatally shot at home and his wife taken into custody.
Los Angeles County sheriff's deputy Crystal Hernandez said Mayor Daniel Crespo, 45, got into an argument with his wife, Levette Crespo.
She is thought to have shot her husband after the couple's 19-year-old son tried to intervene, the officer said.
Mr Crespo was mayor of Bell Gardens, a suburb of Los Angeles, and a city council member for more than a decade.
The couple - high school sweethearts - married in 1986 and Crespo worked as a Los Angeles County probation officer in addition to his duties as mayor.
He was reportedly shot several times and later died en route to the hospital.
Meanwhile, California has passed the first statewide legislation in the nation banning single-use plastic bags.
The bags will be outlawed in grocery and convenience stores to cut down on litter damaging to the environment. The bill will take effect next July.