PITTSBURGH — The FBI is reviewing a violent arrest recorded by a bystander and posted to Facebook, which has one Pittsburgh officer involved on temporary desk duty.

The FBI says Friday it’s trying to determine whether a civil rights violation potentially occurred during Tuesday night’s arrest of 47-year-old Daniel Adelman, of Ravenna, Ohio. If so, the FBI will launch a full investigation.

Adelman acknowledges drinking but says he just tried to help an officer who appeared to be in trouble while arresting another man outside PPG Paints Arena. Police say Adelman interfered in that arrest and Officer Andrew Jacobs has acknowledged punching Adelman repeatedly to subdue him.

The city is conducting an internal investigation as is its Citizen Police Review Board.

The DA’s office says it won’t conduct a “parallel” investigation as long as the FBI is involved.