The reason behind the attack remains unclear. But LAPD Cmdr. Andy Smith says Yealu applied to attend the LAPD academy but was turned down. It was not immediately known when he applied.
Officials say Yealu was a security guard at one point and had a permit to carry a firearm, but that permit recently had been canceled for a reason that hasn't been disclosed by investigators.
Investigators searched the suspect's vehicle, which was parked in the station's parking lot, and found ammunition and a rifle. More firearms were found during a search of Yealu's home Tuesday, including assault semi-automatic weapons, a shotgun, three rifles and two handguns.
Authorities say Yealu walked into the lobby at the LAPD Wilshire Division and West Traffic division office in the 4800 block of Venice Boulevard around 8 p.m. Monday, said he "had a complaint," and then opened fire with a semi-automatic weapon.
One officer was shot multiple times at close range, but he and another officer were able to return fire, hitting Yealu four times. While Yealu remains in critical condition at Cedars-Sinai Medical Center, he has been booked, with his bail set at $2 million.
The injured officer was also taken to an area hospital and is doing well, police said. Authorities earlier said the officer was wearing a bullet-proof vest, but on Tuesday, they said he was not wearing one. They say the seven-year LAPD veteran did have a pistol in his pants pocket that may have saved his life. The pistol deflected one of the gunman's bullets.
"He took a round that would've gone through his femur and maybe his femoral artery in his left front pants pocket, but that round was stopped by his backup weapon that he had in his pocket," said LAPD Chief Charlie Beck.
Authorities say 28 days out of the month, the front door is locked at night, but the door happened to be open Monday night because of a community meeting.
A motive for the shooting has not been determined.