LYNN, Mass.—A Massachusetts State Police trooper is suspended without pay after his arrest for allegedly picking up a suspected prostitute and fleeing when police tried to stop him.

A state police spokesman says 50-year-old Efrain Montanez of Salem was off duty at the time of Friday morning's arrest in Lynn, but was driving an unmarked state pickup. Montanez worked in the gang unit.

He pleaded not guilty to charges including engaging in unnatural acts, failure to stop for police, and assault with a dangerous weapon, the truck. He was released on personal recognizance.

The woman also was charged with prostitution and unnatural acts.

Another off-duty state police veteran is suspended after his arrest last month. He allegedly was driving an unmarked state car erratically and refused to stop for Saugus police. He's due in court next week.

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