A state trooper found liable for killing a 12-year-old boy in 2002 and sued again for citing a motorist he said gave him the middle finger has been sued once more, this time by a Penn Hills man who says the trooper hurled him to the ground and broke his ankle outside a South Side bar.

In a lawsuit filed yesterday in Allegheny County Common Pleas Court, Christopher Strothers, 27, said Trooper Samuel Nassan violated his civil rights outside Rumshakers Bar on July 6.

Mr. Strothers, manager of the West Funeral Home in the Hill District, also sued the state police, saying the agency has allowed Trooper Nassan to remain a trooper despite his "history of acting erratically, violently and with excessive force, and in abusing his authority as a Pennsylvania state police officer."

The complaint cites both of the trooper's previous federal cases as evidence.

On Dec. 24, 2002, he shot Michael Ellerbe in the back after he and his partner, Trooper Juan Curry, pursued the boy following a car chase in Uniontown. A federal jury in March awarded Michael's father $28 million, but rather than continue the legal battle through the appellate process, the state has agreed to pay a $12.5 million settlement.

In the other case, Stephen B. Corey, a US Airways flight attendant, said in a 2005 federal lawsuit that Trooper Nassan gave him an illegal $75 traffic citation after saying Corey gave him the finger in traffic in Robinson.

Mr. Corey denied he made the gesture, although even if he did, his lawyer said, it would have been protected free speech under the First Amendment.

The attorney, Joel Dresbold, said yesterday that the complaint was settled last year for $7,500.

In the latest case, Mr. Strothers said he was outside Rumshakers when a female friend, Jermaine Anderson, got into a verbal dispute with some other women on the sidewalk. City police broke it up, and no one was arrested or cited.

As everyone dispersed, according to the complaint, Trooper Nassan arrived, demanded to know what the problem had been and "violently handcuffed" one of Ms. Anderson's friends and grabbed another.

During that altercation, the complaint says, the trooper grabbed Mr. Strothers and threw him down, breaking his ankle, then hurled him against a car, cuffed him and placed him in the back of his patrol car.

After driving away from the scene, the trooper pulled over, uncuffed Mr. Strothers and let him go, but not before writing him citations for public drunkenness and disorderly conduct, according to the filing.

George Kontos, the attorney for Mr. Strothers, said his client was found guilty of both charges at a magistrate's hearing, during which the trooper said Mr. Strothers showed no sign of a broken ankle on the night of the incident.

But, predicted Mr. Kontos, "those charges will be dismissed (on appeal). My client did not consume one drop of alcohol, nor was he causing any kind of disturbance."

Trooper Nassan, who works out of the Pittsburgh barracks, was not on duty yesterday and his supervisors said they would have no comment.

Mr. Kontos said he will pursue the case in Common Pleas Court, although state police typically seek to have such cases removed to U.S. District Court.