The mother of a young Black man killed by police at a public housing project in Watts joined members of a group calling itself the Revolutionary Communist Party in a protest that briefly shut down traffic Tuesday outside LAPD headquarters.

More than a dozen protesters walked into the street in front of the Los Angeles Police Department’s downtown building about 2:30 p.m., prompting officers to block off First and Main streets for about an hour. The street closure also temporarily barred the public from entering City Hall.

Among the protesters was 47-year-old Lisa Simpson, mother of 18-year-old Apple Valley resident Richard Risher, who was fatally shot July 25 amid what police described as a running gun battle at the Nickerson Gardens public housing complex.

The shooting, which also left a police officer wounded, was reported about 11 p.m. at 112th and Antwerp streets.

According to Simpson, police used “excessive force” in firing dozens of bullets at her son’s back. She said he was unarmed and running away.

Simpson said she came to downtown Los Angeles to seek answers and demand that the officers involved in her son’s death be removed from patrol.

She said two officers eventually gave her their business cards after she “stopped traffic out on the street— because ain’t nobody trying to talk to me about my son.”

Simpson said the other protesters were friends and members of the Revolutionary Communist Party, which according to a pamphlet that was being handed out, is calling for an “actual revolution” to bring about “the New Socialist Republic of North America.”

The small group stood in front of the headquarters building chanting, “No justice, no peace” and using an expletive in their rhyme “ …. the police.”

As the group moved onto the sidewalk, continuing their chants, including a call to “kill the killer cops,” a line of a half dozen officers stood impassively at attention fewer than 20 feet away.

The protest took place not far from a Black Lives Matter sit-in that is now into its 22nd day. The group is demanding that LAPD Chief Charlie Beck be fired.

Melina Abdullah of the Black Lives Matter Los Angeles chapter said that while her group supports Risher’s family, it has different goals than the group that organized today’s protest, and the two entities are unaffiliated with each other.