LOS ANGELES—An off-duty Los Angeles Police Department (LAPD) officer was killed in an apparent exchange of gunfire with three armed robbery suspects in the unincorporated Firestone-Florence neighborhood, and authorities are seeking public help on Jan. 11 to solve the crime. Sheriff’s deputies responded about 9:15 p.m. Monday to the 8700 block of Beach Street, west of South Gate, where they found the officer with gunshot wounds, according to the Los Angeles County Sheriff’s Department. “A black pickup truck approached the male adult victim, an off-duty Los Angeles Police Department officer, and several suspects exited the vehicle,” according to a sheriff’s statement. “An argument ensued and an officer-involved shooting occurred. The pickup drove away in an unknown direction. Deputies from the Century Station responded to the location and transported the victim in their patrol car to a local area hospital where he was pronounced deceased.” A perimeter spanning several blocks was set up as deputies scoured the area for suspects. Officer Fernando …