Video posted by LAPD showed dozens of officers lined up on the street and sidewalk, saluting the officer as his vehicle left the hospital.
The officers, all members of a K-9 dog-handling unit, were wounded Wednesday. Two were released on Thursday, a police statement said.
The gunman, Jonathan Magana, 32, was found dead more than two hours after the shooting. He was on parole at the time of the shooting following a prison sentence for two counts of second-degree robbery, according to the California Department of Corrections and Rehabilitation.
RELATED: 3 LAPD officers shot by parolee at large in Lincoln Heights; suspect dead
3 LAPD officers shot by parolee at large in Lincoln Heights; suspect dies at scene
It was not immediately clear if Magana was fatally shot by police or died of a self-inflicted wound after the shootout and lengthy standoff with police.
Around 4 p.m. Wednesday, plainclothes officers from a drug enforcement detail were looking for Magana. They spotted him walking, but then lost sight of him. They called in uniformed officers to help surround an area and asked K-9 officers to assist in searching it, according to police.
One dog alerted officers to the downstairs room of what appeared to be a converted multiunit living space that was under construction.
Officers surrounded the unit and called on Magana to surrender. When he didn't, they fired a chemical gas. Magana then opened fire, hitting the three officers, who were pulled to a safe location as other officers shot back, according to police. The wounded officers were taken to a nearby hospital in ambulances.
With the area surrounded, SWAT teams were called in and robots were sent in to keep an eye on the suspect. One, equipped with a video camera, went into the room and found Magana, who wasn't moving.
He was later declared dead at the scene.
The Associated Press contributed to this report.