Another cell phone video of last Friday’s violent altercation between SFPD and San Francisco residents at Valencia Gardens surfaced on YouTube today.

The brawl, sparked by plainclothes officers attempting to stop 20-year-old D’Paris “D.J.” Williams for biking on the sidewalk, has ignited allegations of police brutality and inspired a protest set for 5 p.m. tomorrow at Valencia Gardens.

In the new video, officers can be seen carrying a bloodied and groaning Williams away. Minutes later, the video shows a plainclothes officer in a black baseball cap swinging at a man in a gray shirt just before police throw two other men to the ground. Another cell phone video of the incident has been making the rounds on local blogs and news sites over the last few days.

The incident occurred around 3:40 p.m. on Friday, as the Violence Reduction Team was working a plainclothes assignment in the area. “The Valencia Gardens area is a high-crime area,” Officer Gordon Shyy said. “Part of [the Violence Reduction Team’s] routine patrol function is to go through that area.”

Shyy said the undercover officers identified themselves to Williams, who was riding his bike on the sidewalk. They displayed their badges, and asked him to stop, but Williams instead continued riding to an apartment in the complex, Shyy said.

After spending the afternoon observing the Batkid events downtown, Williams was on his way over to see his cousin. “His whole family lives in Valencia Gardens,” said the cousin, Dave, who did not want his last name used.

Instead, Williams made it halfway into his sister’s apartment.

“They attempted to detain him, and he became resistant and combative,” Shyy said.

“They just yanked my brother and dragged him out of the house and slammed him on the ground,” his sister, Christina, said. Stunned, confused, and holding her three-week-old newborn, she followed the officers outside to find out what her brother was being arrested for. That’s when she says officers began pushing her around, which prompted neighbors to react.

“Multiple subjects came out of the building and became combative and formed a hostile crowd,” Shyy said. The officers called for backup.

“Everybody knows him,” Dave said. “That’s why everybody was running out, saying what the hell are y’all doing to D.J.? Kid ain’t doing nothing.”

The resulting melee, captured by at least two cell phone cameras, resulted in four arrests and bloodied faces of at least two of the men. In addition, Shyy said that two officers were transported to a hospital for their injuries.

Antoine Bradford, 22, was booked for assaulting a peace officer and felony resisting arrest, Masai Bradford, Jr., 24, was booked for outstanding traffic and failure-to-appear warrants, and Orlando Rodriguez, 24, was cited for a misdemeanor resisting arrest and released.

Shyy declined to name the police officers involved in the incident.

Williams was booked on assaulting a peace officer, felony resisting arrest, riding his bike on the sidewalk, and for an outstanding traffic warrant.

While many questions still remain, his family wants to know what the Violent Reduction Team was doing enforcing traffic violations.

“They’re undercover narcs,” Dave said. “What are they doing giving bike citations?”

“It’s a violation of the traffic code,” Shyy said. “They are allowed to use that to try to detain this person. This person fled. Can they? Of course. They can write citations for any infractions they observe.”

Williams’ family said no one has heard from him or been able to see him since his arrest.

A KTVU report earlier tonight said that the prosecutor’s office was dropping the charges against Williams, but this could not be independently confirmed. Travis Jansen, a friend, said via email that the family was hoping to pick Williams up tonight.