He told Common Pleas Judge Shelley Robins New that Billy was not perfect, but he was a good son, a "mini me" of his father.
He told the judge that he feels bad about not being strong enough to visit his son's grave. Seeing his son's final resting place, he said, would make him violent, and he doesn't want that.
He also spoke of losing his 25-year job as a supervisor because he was unable to work full days after his son's murder.
"All of this is because of the drunken, selfish, heartless actions of Mr. Tepper. The pain we are going through is so hard, I wouldn't even wish this on you," Panas Sr. said to a sullen Tepper.
Tepper, dressed in an olive-green polo shirt and wrinkled khaki pants, declined to speak.
New told the Panas family that she suspected that Billy would want them to remember his "laughter, love and friendship. He would not want you to live in pain," New said.
"Let this be a closure so that you can go forward."
The judge then sentenced Tepper to life in state prison without parole for the Nov. 21, 2009, murder of his young neighbor.
In addition, New sentenced Tepper to one to two years in prison for possession of an instrument of crime and one to two years for recklessly endangering another person, and ordered him to pay $12,686 in restitution to the Panas family for funeral and other expenses.
Karen Panas asked New for something the judge could not grant: that Tepper be put in solitary confinement twice a year, on Billy's birthday and the anniversary of his death.
"I wanted him to be reminded of that day, of what he did to our son," she said after the hearing.
Tepper, who had been a civil-affairs officer with the city Police Department for 16 years, shot Panas once in the chest toward the end of a melee that broke out in front of the off-duty officer's Port Richmond home.
After Billy and one of Tepper's relatives had finished fighting, Tepper, who was legally drunk, pointed a handgun at Panas, who dared him to shoot.
During Tepper's trial in February, his defense attorney, Fortunato Perri, argued that Tepper had been jumped by Panas' friends and only defended himself.
Lauren Panas, 26, the victim's sister, said that making the loss of her brother harder to take is the fact that he never met her 16-month-old daughter, Madison Billie, whom she named in part after him.
"He was such a kind, loving young man," Lauren said. "He didn't deserve this."
Contact Mensah M. Dean at 215-854-8278 or firstname.lastname@example.org.