Piqui's Law requires judges go through training to better assess family custody cases where the child could be at risk if allowed to be with a dangerous parent.
It would also prohibit family court judges from ordering what's called "family reunification treatments" such as camps, particularly when it involves reconnecting a child with a parent suspected of being abusive.
Mom of slain 5-year-old South Pasadena boy talks about last moments with her son
Mom of slain South Pasadena boy speaks out
The bill is named for Aramazd "Piqui" Andressian, Jr. of South Pasadena, who was 5 years old in 2017 when he was murdered by his father during a bitter custody battle.
Aramazd Adressian Sr. is now serving prison time for the killing.
Ana Estevez, Piqui's mother, urged Newsom to sign Piqui's Law, which was approved by the Legislature last month.