A Boston Police sergeant was arrested after cops say he was “highly intoxicated” when they responded to a rear-end collision in Brookline. “Trooper, do you understand who I am?” off-duty BPD sergeant Mark McKeown allegedly told a state trooper trying to perform a field sobriety test on the sergeant.

Detective Mark Joseph McKeown, 52, of Dedham, was initially slated for arraignment Monday in Brookline District Court on a single OUI count, but the hearing was delayed until Feb. 4, according to legal filings.

An off-duty sergeant with the Boston Police Department is accused of driving drunk and crashing into another car on VFW Parkway. The sergeant, Mark McKeown, was also described in a police report of behaving in a vulgar manner toward Brookline police officers who arrived at the scene of the crash.