Oct 9, 2013 7:24 PM by NBC News
(NBC News) A New York police officer was formally charged Wednesday as part of a group of motorcycle riders that surrounded an SUV, battered the vehicle and attacked the driver.
Undercover detective Woljcieh Braszczok has admitted he was not only at the scene, but took part in the violent attack and didn't come forward until three days after the assault.
Braszczok was formally charged with riot and criminal mischief.
Police sources say he rode away before driver Alex Lien was pulled from the vehicle, then punched and kicked repeatedly by the angry mob.
NYPD internal affairs officers say they are now looking into the possibility as many as five other off-duty officers may have taken part in the unauthorized motorcycle rally.