Investigators believe the 14-year-old opened fire in the shooting, which occurred about 5 a.m. in the 3400 block of South Central Avenue as the officer was arriving to work, according to the LAPD.
The officer "felt a sharp pain to the back of his head" while driving, and was able to run to a fire station across the street from the police station for medical treatment, LAPD Assistant Chief Rob Marino said at a news conference. Los Angeles firefighter-paramedics transported him to a hospital in stable condition, and he is expected to recover.
The officer's personal vehicle, a pickup truck, was seen partially on a sidewalk in front of the police station after apparently jumping the curb. The truck's passenger-side window was shattered.
"There's no indication he had been targeted at this point," Marino said.
Officers fatally shoot man threatening own family with cleaver in Palms, LAPD says
The shooting prompted a massive response from the victim's fellow officers, who set up a perimeter in the area.
An officer who witnessed the immediate aftermath of the shooting put out a description of the suspect, who was take into custody several blocks from the scene.
In the pre-dawn hour, several investigators scoured the street with flashlights, apparently searching for spent shell casings and other evidence.
The juvenile was in possession of a handgun when apprehended, Marino told reporters.
The wounded officer was identified only as a 20-year veteran of the department who is assigned to juvenile crimes. The name of the suspect, a minor, was also withheld.
Police Chief Michel Moore tweeted: "Grateful our officer will survive this unprovoked attack. Just spoke with him by phone. ... Too many guns in too many hands."