The scene outside the yellow, sun-baked apartments of Nickerson Gardens was tense.
The night before, police had killed an 18-year-old man in a shooting that left an officer wounded. On Tuesday morning, a handful of officers walked through the Watts housing project, one of L.A.'s most notorious, trying to calm everyone down. Some residents shouted profanities and insults about police.
"It's going to be a long day," said Officer Aaron Thompson, who's worked the project for the last three years.
Suddenly, as Thompson and another officer were speaking with residents, a shout was heard from down the street. The officers took off running as neighbors spilled out of their apartments and followed. In a small parking lot, a crowd had gathered around a young man collapsed on the hot asphalt.
"Breathe, son," his mother wailed. "Breathe."
A half-dozen officers surrounded the man, pumping his chest as they started CPR. One ripped away her uniform, using it to clear vomit from the man's mouth. Others pressed their mouths to his, trying to revive him from what they thought was a drug overdose.
For long minutes, the officers kept pumping, kept working, to keep him alive. The man's mother shouted prayers as Thompson held the man's head.
"Come on, D," the officer told him.
The fast-moving drama in Nickerson Gardens underscored the complicated duality of modern-day policing. Twelve hours before, the police killing of a black 18-year-old had infuriated the neighborhood. That anger, however, melted away — at least temporarily — when officers ran to another black man who needed help.
"If those officers never came," one woman remarked after an ambulance arrived, "he probably wouldn't be here."
Monday night's violence came after a series of deadly shootings around the country — both by and against police — that has heightened tensions amid a roiling national debate over how officers use force, particularly against African Americans. Police across the country, including those working in L.A., have been on edge in recent weeks after attacks that killed officers in Dallas and Baton Rouge, La.
The events leading up to the Nickerson Gardens shooting began about 11 p.m. Monday, when officers patrolling the housing project saw a group of people near 111th and Antwerp streets, the LAPD said.
Officers had been paying particular attention to the area because of a deadly dispute between a gang affiliated with Nickerson Gardens and a rival group associated with the nearby Jordan Downs housing project, LAPD Chief Charlie Beck said.
The feud, which police believe began with a July 15 shooting in Hawthorne, led to a series of back-and-forth shootings that have left three people dead and eight wounded, Beck said.
The officers on patrol saw what they believed to be a group of gang members and stopped to investigate, Beck said, citing a preliminary investigation. One man began to run, then turned and started shooting at the officers, who fired back, killing him, Beck said.
One officer was hit in the arm and taken to a hospital for treatment. The dead man was identified by his parents as Richard Risher. He was the 10th person fatally shot by on-duty LAPD officers this year.
Beck said a gun was found in "close proximity" to Risher's body. The officers were not wearing body cameras, he said, but investigators are looking at footage from their patrol car and cameras belonging to the housing authority.
Based on the initial investigation, Beck said, it "appears that the officers responded to a deadly threat appropriately."
Risher's mother, Lisa Simpson, learned about her son's death when her daughter called her with the news late Monday night. Simpson, 47, was stunned.
She called Risher's father, who shares the same name as his eldest child. Richard Risher, 39, didn't believe her at first and hung up the phone. When she called back, he said, he got into his car and sped to the housing project.
The parents didn't leave the housing project until mid-morning Tuesday. Each questioned the police account, saying they didn't believe their son had a weapon. The 18-year-old was with a group of people, his father said, and could have been running away from the gunfire when he was shot by police.
Risher said that his son had been spending time in Nickerson Gardens, but that he was encouraging the teen to move to his San Fernando Valley home to finish up classes and earn his high school diploma. The younger Risher liked basketball and music, his parents said, and to make people laugh.
"I always thought that my kids were going to outlive me," said Simpson, a paralegal who lives in Apple Valley. "If God let me trade places, I'd trade places with my son right now."
The largest housing project west of the Mississippi River, the 1,000-plus-unit Nickerson Gardens was plagued for years by gang shootings and fights with police. After several years of calm, violence there flared in 2010, when a gang dispute led to a series of shootings that left five men dead over a span of about six weeks.
In recent years, the LAPD flooded Nickerson Gardens with officers specifically focused on getting to know the people who live there in hopes of reducing crime by improving relationships between police and residents. The efforts appear to have paid off: Killings and shootings are down this year within the LAPD's Southeast Division, which includes the housing project.
"It used to be a lot worse," said Anthony Lim, a 24-year-old who's lived in Nickerson Gardens for nearly his entire life. "But I still wouldn't consider it good."
Thompson, the officer who spent Tuesday trying to calm tempers, is one of the officers focused on Nickerson Gardens. At one point on Tuesday, he approached Risher, explaining the lengthy investigation that would follow his son's death and telling him to reach out if he had any questions.
"Hang in there, man," Thompson said.
"They're all upset and frustrated — as they should be. It's a soul lost," Thompson told a Times reporter. "I just try to help them."
A half-hour later, Thompson was one of the officers desperately trying to save the unconscious man in the parking lot. He and others tried to resuscitate the man mouth-to-mouth, pausing to spit out the vomit they had cleared from his throat.
Paramedics arrived to take the man to a hospital. One officer turned to the crowd that had been watching.
"They got a pulse," he said.
As the group of onlookers dispersed, the officers wiped sweat from their faces. Two were missing their uniforms, having stripped down to their bulletproof vests. As they walked away, a man stepped toward the sidewalk and shook their hands.
"Y'all did good," one woman said.
Follow me on Twitter: @katemather.