By Daily Mail Reporter and Ryan Gorman PUBLISHED: 11:47 EST, 5 October 2013 | UPDATED: 21:07 EST, 5 October 2013 An off-duty undercover New York City police detective who witnessed a violent confrontation between an SUV driver and a group of bikers last week but failed to report it has been suspended as two of the alleged attackers turned themselves in. Reginald Chance, 38, who police say is the biker seen in a video smashing his helmet against Alexian Lien’s SUV and yanking him out of the vehicle, came forward Friday night along with 35-year-old Robert Sims. Sims, of Brooklyn, has been charged with attempted assault, gang assault and criminal possession of a weapon. The 35-year-old biking enthusiast has been identified as the person seen trying to open Lien's door, according to the New York Daily News.
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Reginald Chance, 38, and Robert Sims, 35, turned themselves in Friday
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Injured biker Edwin Mieses Jr now faces permanent paralysis
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Off-duty undercover narcotics officer placed on modified duty as NYPD investigates why it took him four days to come forward
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A number of off-duty corrections officers may also have been present
Fears: Lien needed stitches after he was attacked by bikers in @placeholder on Sunday as he tried to protect his wife and child.