That didn't take long -- not even a day after video came out showing an undercover NYPD detective taking part in that vicious beating by a biker gang, the cop has been arrested.

Wojciech Braszczok surrendered Tuesday shortly after a Manhattan district attorney signed off on his arrest. Although the video clearly shows that he rode off on his motorcycle before the assault actually occurred, he's also seen using his helmet to break in the back window of the SUV of Alexian Lien. He insists he didn't intervene out of fear of breaking his cover.

Authorities say that Braszczok will be charged with obstruction of justice for lying about what happened. He waited four days to come forward after the September 29th incident, and he initially told investigators that Good Samaritans were helping the victim when he reached the scene.

Source: New York Daily News