An undercover New York City police detective pleaded not guilty Wednesday to gang assault in a motorcyclist-SUV highway melee captured on amateur video, as prosecutors said they continued to look for additional participants.

Wojciech Braszczok was lead in and out of Manhattan state Supreme Court by his lawyers, with his hood over his head and a plaid scarf covering his face. Inside court, he said two words: “Not guilty,” during the short arraignment before putting the getup back on and heading back out. His lawyer John Arlia had no comment.

The Sept. 29 encounters on a Manhattan highway and side street were partly caught on a helmet-camera video posted online. Prosecutors handed over video to defense attorneys, but judge

After the Range Rover SUV driver bumped a bike that had slowed in front of it, motorcyclists surrounded and converged on it, according to investigators. The SUV driver fled in fear for the loved ones riding with him and ran over a biker, and motorcyclists chased him, pulled him from the vehicle and attacked him, police and prosecutors say.

The SUV driver, Alexian Lien, has not been charged with any crime.

Prosecutors have said Braszczok shattered the SUV’s back window.

Braszczok was off duty at the time. Prosecutors said he did nothing to stop the assault or summon help, didn’t report having been there to his superiors for a few days, and wasn’t straightforward when he did.

The detective was stripped of his gun and badge after internal affairs investigators discovered he saw at least part of the confrontation. He initially told authorities and his union that he didn’t intervene in the attack partly because he works undercover.

Arlia has said that the window Braszczok is accused of breaking already had a sizeable hole in it. The detective didn’t know other participants in the rally, which was organized online, and he pursued Lien only to prevent his flight after the SUV ran down and seriously injured motorcyclist Edwin Mieses Jr., Arlia said previously.

Three other suspected participants also pleaded not guilty Wednesday. One, Clint Caldwell, is trying to sever his case from the other 10 charged in the incident. His lawyer, Raymond Colon, said his client is seen on video clearly stepping away, and did not participate in the attack.

“You can search every stone in the city of New York, you won’t find any evidence whatsoever of his ties to any of these other co-defendants,” he said.

Assistant District Attorney Josh Steinglass said there may be more arrests. Supreme Court Justice Maxwell Wiley asked that defense attorneys not copy the video evidence handed over in the case.

(AP)