Disgraceful...

Bike cop joined in on SUV beatdown, hit vehicle

The scene of the biker mob's attack on an SUV driver.

An off-duty undercover cop who claimed he took no active role as fellow bikers pulled a Manhattan dad from his SUV and beat him to a pulp was actually pounding the vehicle with his fists during the height of the bloody road-rage attack, sources told The Post.

The cop, a seven-year veteran, had told investigators he didn’t help the injured man because he rode up to the scene as the beating was nearly finished, sources said.

But video footage clearly shows otherwise, disgusted sources said Monday — and Internal Affairs Bureau higher-ups want to nail the officer.

Probers believe their hands are tied, however, sources said, because authorities already dropped charges against another biker, Allen Edwards, 43, of Queens, who allegedly punched the rear window of Alexian Lien’s Range Rover before Lien’s beatdown in front of his wife and 2-year-old daughter.

At the time, the chief of the Manhattan district attorney’s Trials Division, Karen Friedman Agnifilo, defended the move, saying, “Prematurely charging individuals with low-level crimes does not further the goals of the investigation and could weaken the cases we expect to bring against the perpetrators of serious crimes.”

Still, the undercover cop will likely face internal charges. He didn’t even tell his bosses that he was with the bikers — much less at the scene of the crime — until Wednesday night, more than three days after the attack.

The unnamed officer has already been placed on modified duty and turned in his gun and badge.

“I think we all, no matter what your job is, have an obligation to help one another,’’ Mayor Bloomberg said on MSNBC’s “Morning Joe’’ on Monday, in response to questioning about the officer’s actions. “And if you see somebody getting beaten up, you know, let’s go jump in and stop the fight.”

Another off-duty officer also was among the bike pack, but he wasn’t anywhere near the scene of the beating, sources have said.

The explosive development came as yet a fourth biker was set to be arrested in Lien’s beating. The 29-year-old Brooklyn man was among five or six bikers who attacked the 33-year-old Columbia grad in Upper Manhattan on Sept. 29, sources said, adding he would likely face gang-assault and other charges.

The biker was tracked down after cops traced his license plate, sources said. The bike is actually registered to his uncle, who he borrowed it from, sources said.

Cops are searching for at least two more suspects, whose photos — from video footage taken at the scene — they’ve released.

Meanwhile, Christopher Cruz, 28, who allegedly started the chain of events by slowing down his bike to let his pals ahead — leaving Lien to bump his car into him — said in an interview aired Monday that he didn’t “feel responsibility’’ for what happened.

“I was looking over my shoulder to see where my friends were,” he told ABC News. “I wanted them to pull in front so I could follow them. I didn’t brake, but when I looked over my shoulder, my hand came off the throttle a little, but the driver didn’t slow down at all and bumped me.
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