SAN DIEGO — Starting May 1, deadly shootings involving law enforcement in San Diego County will be investigated by a separate local agency, not an internal probe by the department’s own detectives.

The new change will now require the San Diego Police Department to investigate fatal police shootings for other departments in the county and shootings involving sheriff’s deputies. The San Diego County Sheriff’s Department, meanwhile, will conduct investigations for SDPD shootings.

“The bottom line of what you heard today, and the reason this is a great step: No agency would be investigating its own officer-involved shooting,” said San Diego District Attorney Summer Stephan.

If both the sheriff’s department and police are involved in a shooting, the Chula Vista Police Department will conduct the investigation.

“All law enforcement agencies in our region recognize the need for transparent and independent criminal investigations, and review of all peace officer-involved shootings and significant uses of force,” said CVPD Chief Roxana Kennedy.

If there is an incident involving the use of force that does not result in a death, the same agency involved will still investigate.

The new protocol, which was agreed upon by all the law enforcement agencies in San Diego, has been in the works for over a year.

The agency doing the investigation will have 90 days to complete it, then the district attorney’s office will have 90 days to review the investigation and determine if the use of force was legally justified or not.

“I’m very proud. We are the only region in the state that is doing this in order to better serve and protect the public,” Stephan said Wednesday.