A federal judge on Monday dismissed a complaint of excessive force filed last year against Steven Webster, the head of detectives for the South Portland Police Department.

Webster did not violate Rosanna Morelli’s constitutional rights when he detained her during a prostitution sting, U.S. District Judge George Singal ruled.

Police set up the sting on March 3, 2006, at the Merry Manor Hotel in South Portland.

Morelli received the call through an escort service, Serena’s Heaven on Earth, and met an undercover officer at the hotel. When she suspected the man was an officer, Morelli angrily left the hotel room, according to court documents. She allegedly took $20 from a stack of bills the officer had set on a table, saying he should pay for her gas money.

Webster was in an adjacent room, watching the events unfold on a surveillance camera. He had seen Morelli take money, and he attempted to stop her from leaving.

There was a confrontation in the hallway and Webster grabbed her wrist and pinned her against the wall. Webster then brought her back into the hotel room for questioning. Morelli was then released and not charged with any crimes.

Morelli, 53 at the time, filed a civil complaint in federal court last May, alleging Webster used excessive force and did permanent damage to her right shoulder, arm and lower back.

Judge Singal ruled that Webster had reasonable suspicion to seize and detain Morelli, and that he used a degree of force reasonable under the circumstances.