Officers are trying to stop any retaliation after 20-year-old Trazhan Heights was killed Saturday night during a gang-related shooting near N Marks Ave & W McKinley Ave in West Central Fresno.
An 11-year-old at his home was also shot in the arm.
Fresno Police Chief Jerry Dyer said the problems were sparked Friday at the funeral of Zurich Chatman.
Officers were told there would be retaliation if an arrest was not made.
Detectives have not ruled out whether heights may have been involved in Chatman's murder.
The chief says even though many of the recent shootings are gang-motivated, Chatman was not a gang member.