A lawyer with the New York City detectives' union says an undercover officer present at a motorcycle rally that turned bloody did not witness the attack on an SUV driver.

Attorney Phil Karasyk (KEHR'-uh-sehk) says the detective was off duty when he joined the Sept. 29 rally.

He rode up Manhattan's West Side Highway after the SUV struck a biker. He followed the other bikers because he thought there had been a hit-and-run.

Karasyk says the detective later saw motorcyclists attacking the SUV. But he did not see the driver, Alexian Lien (LEE'-ehn), pulled from the vehicle.

The detective did not come forward to disclose his presence at the scene for three days. Department officials are looking into the delay.