HANFORD, Calif. (KSEE/KGPE) — A Hanford birthday party turned deadly Saturday night when a Kings County welfare fraud investigator allegedly murdered his friend, an off-duty Lemoore police officer, and shot his father before committing suicide over a domestic violence incident with his girlfriend, the Kings County Sheriff’s Office said.

Deputies were dispatched to the 8000 block of Eddy Street around 9 p.m. for a report that three people had been shot at a residence.

Jonathan Diaz, 31 (Courtesy of the Lemoore Police Department)

Deputies found two dead men, identified as Jonathan Diaz, 31, and Ramiro Trevino Jr., 32, and one critically injured man, Ramiro Trevino Sr. at the residence, Cmdr. Mark Bevens said. Trevino Sr. was taken to Kaweah Delta Medical Center in Visalia and is listed in critical condition.

Witnesses told detectives that Trevino Sr. and Diaz along with other people at the party intervened in a domestic violence dispute between Trevino Jr. and his girlfriend and were able to get the woman to safety.

Diaz and Trevino Sr. encountered Trevino Jr., who had armed himself with multiple firearms, to further diffuse the situation, Bevens said. It was at this point that Diaz was fatally shot and Trevino Sr. was shot and critically injured.

Deputies then think Trevino Jr. committed suicide by shooting himself.

Sunday afternoon, county administrative officer, Rebecca Campbell, released a photo of Trevino Jr.