Los Angeles police Tuesday released some details surrounding the fatal shooting of an armed man by an LAPD officer last week in a housing project.

Shortly after 5 p.m. on Thursday, anti-gang Officer Manuel Castaneda and his partner were patrolling the grounds of the sprawling Imperial Courts public housing project in Watts in a marked police vehicle, according to a LAPD statement.

The officers "encountered three known gang members," in a courtyard area near the intersection of 114th and Grape streets, according to police sources and a formal statement released by the department.

When one of the men, 18-year-old James Davis, walked away from the approaching police vehicle, the officers grew suspicious and got out of the car to investigate, the statement said. Davis grabbed a woman standing nearby and, in an apparent attempt to distract the officers, shoved the woman in their direction and then broke into a sprint, according to the statement.

The officers gave chase and "noticed that Davis appeared to be grasping at or about his waistband area," according to the statement. Castaneda, who has been an LAPD officer for 5 1/2 years, fired his handgun when Davis pulled out a semi-automatic handgun and pointed it back toward the officers as he ran, the statement said. His partner, who has not been identified, did not shoot.

A loaded 9mm semiautomatic pistol was recovered at the scene, according to the LAPD's statement. A police official with knowledge of the shooting, who requested that his name not be used because the investigation into the incident is ongoing and confidential, said Davis was struck in the back.

That revelation is likely to further stoke anger that has simmered among police critics and residents of Imperial Gardens since the shooting. In the aftermath of the shooting, dozens of angry onlookers swarmed the scene, prompting police commanders to briefly declare a tactical alert throughout the department and call in a large number of officers to disperse the crowd.

Through an LAPD spokesperson, department officials declined to provide further details about the shooting, including the specifics of how Davis turned, the officers' position in relation to Davis at the time Castaneda fired, and why Castaneda's partner did not shoot.

Capt. Phillip Tingirides, who commands the LAPD division that patrols Watts, could not comment on the specific incident, but said there are scenarios in which a gun-wielding suspect can be shot in the back during a foot pursuit. For example, the suspect could turn to point his weapon at an officer and then turn back to continue running. Or, if two officers are chasing the suspect from different directions, the suspect's back could be exposed to one officer when he turns to point his weapon at the other, Tingirides said.

At a news conference Tuesday, some people who claimed to have witnessed the shooting offered accounts that differed from the LAPD's version of events. Jubilee Shine, a spokesman for the Coalition for Community Control Over the Police, which held the news conference, acknowledged that Davis was carrying a handgun, but challenged the notion that he pointed it at the officers.

Instead, he said, witnesses claimed that Davis dropped the handgun as he fled and that Castaneda fired after seeing the weapon fall to the ground. The challenge of resolving such conflicting accounts will fall to detectives from the LAPD's Force Investigation Division, which investigates incidents in which officers use serious force.

It typically takes several months to complete shooting investigations, in which witness accounts, officer accounts, bullet trajectories and other evidence are compiled. The information is passed on to command staff, who determine whether an officer acted within LAPD policies.

Paul Weber, president of the union representing police officers, said Davis' "death was a result of his own actions." "This shooting could have been easily avoided," Weber said in a prepared statement.

"Mr. Davis should not have been carrying a fully loaded semiautomatic pistol. He should not have run. He should not have drawn and pointed the pistol. Had he refrained from any of these things Mr. Davis would be alive today."