Wojciech Braszczok did not speak to reporters at his court appearance Wednesday in Manhattan, the New York Daily News reported.
Alexian Lien, who was in an SUV with his wife and child, was beaten Sept. 29. Prosecutors say bikers participating in the annual ride around New York City pursued Lien after he ran over a motorcyclist while trying to get away from the group. The bikers caught up with him near the George Washington Bridge and pulled him from his vehicle after breaking windows.
The News said it obtained investigative reports that show Braszczok, an undercover detective, changed his story several times. Investigators said he initially said he did not try to stop the attack because he did not have his shield or gun at the time.
A few days later, he said "there were too many people there -- it was one against a lot of people."
In one interview, he said he was not present when Lien was beaten. The News said the police officer also told an investigator he was there with other members of a "police officer crew."
Braszczok faces up to 25 years in prison if he is convicted of gang assault.