SAN FRANCISCO – A San Francisco police officer who killed himself after being pulled over by police in a neighbouring city was under investigation for child sexual abuse in Las Vegas, authorities said Tuesday.

Antonio Cacatian, 49, shot himself Monday afternoon after San Francisco police requested help arresting him. Police in the nearby city of Richmond, where Cacatian lived, pulled him over in a shopping mall parking lot and officers retreated to their cars when they heard a gunshot, Lt. Felix Tan said.

Tan said the windows of Cacatian’s vehicle were tinted and officers could not see inside. One used a gun that fires bean bags to break a window and discovered Cacatian’s body inside.

Cacatian was under investigation over allegations that he may have committed sexual acts with a child under the age of 14 in 2014, Las Vegas Metropolitan police spokeswoman Laura Meltzer told the San Francisco Chronicle.

Cacatian apparently knew the child, Meltzer said.

Detectives hadn’t secured a warrant for his arrest but informed San Francisco police about the case last week, Meltzer said.

Cacatian was a 9-year veteran of San Francisco’s police department.