PORT RICHMOND residents said yesterday that an off-duty officer who fatally shot a young man during a large street fight Saturday night is a bully who's maced their kids and brandished his gun around the neighborhood for years.

Police said that the officer had been trying to break up a street brawl about 11 p.m. when he was attacked, leading him to shoot unarmed William "Billy" Panas Jr., 21, once in the chest.

But Port Richmond residents, who identified the officer as Sgt. Frank Tepper, said that the fight had spilled out from a party at Tepper's own home on Elkhart Street near Edgemont, and that many of his relatives, including his own son, had been involved.

Several neighbors also claimed that Tepper was visibly intoxicated when the shooting occurred.

"He just shot my son in the heart," said Panas' father, William Panas Sr. "He's supposed to serve and protect, not kill."

Travis Marko, 19, one of eight friends with Panas on Saturday night, said the group had decided to get Chinese food when the fight on Elkhart Street caught their attention.

They decided to walk by the fight and one of the members of their group was sucker-punched by one of the fighters, Marko said.

Their group then got swept into the fight. Marko said that Tepper had punched him and that the officer had come out of his house holding a clear plastic cup.

"You saw clearly that he was drunk," Marko said.

When the punch leveled Marko, his friends dragged him away from the fight, he said. He claimed that as they were leaving, Tepper pointed his gun at them and said: "Back up or I'll shoot you."

Panas Jr. was fighting with someone on the ground as Marko and the others ran away, he said.

They were a few houses from the scene when he heard the gunshot that killed his friend, he said.

Panas Sr. said that his son was fighting with Tepper's son on the ground during the melee and that he didn't run when Tepper allegedly made the threats.

"He said, 'I'll shoot you,' and my son said, 'No you won't,' " Panas said that witnesses told him. "He said 'Oh, no?' And then, boom!"

Lt. Frank Vanore, police spokesman, would not comment on whether Tepper had called 9-1-1.

Police confirmed that members of Tepper's family had been involved in the fight but declined to say if Tepper had been intoxicated.

Neighbor Chris Bolduc, who watched the police response after the shooting, said that police had put Tepper in the front seat of a patrol car.

"He was obliterated out of his mind," Bolduc said. "I definitely know for a fact that he was drunk."

Vanore said several independent witnesses had said that Tepper identified himself as a police officer before the shooting, though Marko denied that claim.

"I know there is a contrary side to all these things," Vanore said. "Until this investigation is complete, I can't get into the details."

Panas said numerous people had contacted his family to claim that Tepper had harassed them or their children.

Debbie Spencer said that in 2002 Tepper, dressed in civilian clothing, walked by her then-17-year-old son and his friend on the street and demanded to know who they were.

Tepper did not identify himself as a police officer, Spencer said, so her son demanded to know who he was. Tepper then fired pepper spray in the face of her son and his friend, she said.

Blinded, her son started swinging his arms and hit Tepper, not knowing he was a cop, she said.

Tepper called for backup and had Spencer's son arrested for assault on a police officer, she said.

Spencer said that within 25 minutes of the altercation, she went to Tepper's house, where he claimed that he wasn't required to identify himself as a police officer to her son. Spencer said that she could smell beer on Tepper's breath and that he appeared intoxicated.

"My father was a cop for 36 years in Philadelphia," Spencer said. "My son respected police up until that day." Spencer said that she never filed a civilian complaint, out of fear for her son, she said.

"But my son was one of the lucky ones," she said. "My son lived. It could have been my son that was shot."

Christine Killian said that in 2001 her son was playing basketball in the park across from Tepper's house about 10 p.m. Tepper came outside brandishing his gun and telling him to get off the court and be quiet, she said.

Killian said that she and her boyfriend confronted Tepper, but because he still had the gun in his hand during their conversation, they decided to walk away.

She said they went to the local police district and filed a report, but nothing ever came of it.

"It's sad," she said. "Something has to be done because he's been getting away with this for years."

Calls by the Daily News to the department's Internal Affairs Bureau about civilian complaints filed against Tepper were not returned yesterday.

Other residents talked of a video of Tepper shooting an opossum on city streets and how they didn't feel like it was safe to park their cars in front of his house or even to tread on his sidewalk.

According to city payroll records, Tepper was hired in 1993. Last year, he made $67,688 - $4,811 of which was for overtime, records show. Tepper is a member of the Civil Affairs Unit, which is responsible for policing demonstrations, picket lines and other forms of public assembly.

Prior news reports indicate that Tepper shot a robbery suspect during a foot pursuit in March 2002. Tepper claimed that the suspect, who survived, had fired at him first.

Vanore would not comment on Tepper's record.

In Saturday's case, Tepper was the only one armed, police and neighbors said. Police reported no arrests in the crowd for the alleged assaults against Tepper.

Panas Jr.'s only arrest was for driving under the influence, according to court records. A status hearing in the case had been scheduled for January.

His family said that he was a loving son who helped care for his mother during her recent battle with cancer. He had just received his barber's license and was planning to open his own shop, said his aunt, Debbie Ditro.

"He had the biggest heart you could ever imagine," she said. "And now his own parents' hearts have been ripped out."

Tepper has been placed on desk duty while an investigation is conducted by Internal Affairs and the District Attorney's Office.

Through a family member yesterday, Tepper declined to comment about the case.