BROOKLYN - A fifth Brooklyn man has turned himself in for the motorcycle gang assault of an SUV driver in Manhattan.

According to investigators, 31-year-old James Kuehne is now among seven people facing charges in the attack, including undercover Detective Wojciech Braszczok, who was unmasked in a courtroom Wednesday.

Prosecutors say Braszczok was an active participant in the Sept. 29 beating of Alexian Lien, but his lawyer argues that the same video that allegedly incriminates him will actually prove his innocence.

Braszczok claims he did not intervene or report the incident for two days because he feared blowing his cover.

Authorities say they are still actively searching for another three men in connection with the melee, and have released photos in hope that someone will come forward with information.

In the latest video of the attack to go viral on YouTube, Lien is seen lying on the pavement after an altercation on the West Side Highway. Lien was surrounded by the gang after hitting the rear tire of one of the bikes. He then took off in his SUV, running over one biker, before being chased down.