Seven years ago, an Internal Affairs investigator warned Philadelphia Police Officer Frank Tepper, now accused by neighbors of fatally shooting an unarmed 21-year-old man Saturday night in a fit of temper, against taking the law into his own hands while off duty.

Tepper had gone in search of a teenager who bullied the officer's 8-year-old son at a playground near the family's Port Richmond home, according to the report. Tepper ended up in a scuffle with local youths, spraying Mace at them, taking a punch to the face, and drawing his gun before on-duty police arrived.

Tepper's actions, the report said, "could have resulted in numerous injuries with the very real possibility of deadly force being used by him during this confrontation. Police Officer Tepper would have fared better with the assistance of on-duty police officers as opposed to the situation which led him to face a hostile crowd of youths alone."

Saturday night, Tepper again chose to confront a volatile situation instead of waiting for backup.

When a brawl erupted on Elkhart Street in front of Tepper's house during a family party, he went outside to break it up, police said. Tepper told police he was attacked and fired his gun in self-defense.

The shot killed William Panas Jr., who lived nearby and who eyewitnesses said also had been trying to stop the fighting.

Witnesses said Tepper appeared intoxicated during the fight, which included members of his family and others from the neighborhood. No one but Tepper was armed, and police have reported no arrests in the fight.

Police Lt. Frank Vanore said he could not say whether Tepper called 911 before getting involved or whether he was drunk. Tepper has not returned calls seeking comment.

Panas, who lived with his parents and had planned to open a neighborhood barbershop, will be buried Saturday, said his father, William Sr.

Many members of the community have come forward to the Panas family, expressing their support and sharing stories about the younger Panas.

"I'm hurting," the elder Panas said yesterday. "We all are. But to know my son was respected and loved is a good feeling."

Police Commissioner Charles H. Ramsey has also called, Panas said, and told the family that Tepper could face charges if the investigation reveals the shooting was not justified.

"For Mr. Ramsey to call me personally was very reassuring," Panas said. "I don't want sympathy for me and my wife. I just want justice."

Since the younger Panas' death, residents of his Port Richmond neighborhood have spoken out about their experiences with Tepper. Some have reported seeing Tepper brandish a gun or fire shots into the air. Others recalled seeing him shoot an opossum in the street. Still others have reported a long history of feuding with or threatening the area's teenagers and young adults.

Debra Spencer said she had been afraid of Tepper since 2002, when he used Mace on her son during the fight over the harassment of Tepper's young son.

"My son didn't know who he was when Frank came at him," Spencer said, who later sought out Tepper to question him about the scuffle. "I asked Frank if he had identified himself as a cop, told the kids he was police. He said, 'I don't have to.' "

The Police Department's guidelines for off-duty officers dictate that officers call 911 before taking any police action, Vanore said, and all such actions are automatically reported to Internal Affairs. Ultimately, Ramsey reviews each case.

Every time an officer fires a gun, either on or off duty, the gun is confiscated. A supervisor then arrives to take the officer to Internal Affairs, which investigates the incident.

Tepper, who joined the department in 1993, works in the Civil Affairs Unit, whose assignments include demonstrations and labor disputes. He has been placed on desk duty during the investigation, standard procedure for officers involved in shootings.

Tepper previously worked as a patrolman in the 15th District, which includes parts of North Philadelphia.

Tepper has been the target of seven complaints from citizens alleging that Tepper assaulted them, swore at them, or otherwise behaved inappropriately. Police sources said it was not unusual for a 16-year veteran of any police force to amass complaints, particularly when the officer worked as a patrolman.

Though Tepper was cleared of most charges, including the complaints of abuse, he was admonished for his behavior several times, according to the reports from Internal Affairs.

In 1995, Tepper, while off duty, got involved in a car chase after two men allegedly catcalled his fiancée and another woman. Tepper had been in a bar earlier wearing most of his uniform, according to the Internal Affairs report, in a violation of department policy.

Tepper told police that the men's car hit him when he tried to tell them to leave and that he had followed them to make an arrest when they drove away. The investigator assigned to the case observed that "Officer Tepper's version of events seems to be lacking the whole truth."

In 2001, an Internal Affairs report found that Tepper and another officer tried to force a man they arrested to apologize to them for resisting arrest.

In the 2002 incident, in which Tepper confronted a group of teenagers, the Internal Affairs report found that he violated the department's guidelines for off-duty officers.

Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com.