A federal jury ended its first day of deliberations Monday without resolving a claim that the City of Philadelphia ignored signs Officer Frank Tepper was a reckless and dangerous cop before he fatally shot a 21-year-old man outside his Port Richmond home in 2009.

After listening to closing arguments and deliberating three hours, the panel sent a question late in the day to U.S. District Judge Legrome D. Davis. The judge didn't disclose the nature of the question but told the jury he and the lawyers would answer it when they return Tuesday.

The civil rights case, brought by the parents of William "Billy" Panas, Jr., represents a coda of sorts to one of the more divisive cases involving city police.

Tepper had 16 years on the force - and dozens of mentions in police Internal Affairs files - when he emerged from his Elkhart Street home the night of Nov. 21, 2009 to disperse a group of young men arguing out front. Tepper was waving a gun and may have identified himself as a cop, witnesses said.

Panas told the others not to worry. "He won't shoot anybody," Panas said.

Tepper then turned to the young man and fired into his chest.

Convicted in February of first-degree murder, Tepper, 46, is serving life in prison. He made no attempt to contest the civil claim and hasn't attended the trial.

But the panel of five women and three men have been asked to resolve larger and more complex questions: Was Tepper acting as an officer that evening? And if so, did the city and its police department deserve some of the blame?

James J. Binns, the lawyer for Panas' parents, told jurors that the city and police department bosses showed "deliberate indifference" by ignoring years of red flags and complaints about the officer's conduct or meting out only cursory punishments. They are seeking both compensatory and punitive damages.

Binns called a parade of witnesses in the weeklong trial who described a half-dozen incidents between 1995 and 2002 in which Tepper, often fueled by alcohol, brandished his badge or a gun and harassed or assaulted young men in and around his neighborhood but evaded serious disciplinary action.

"He didn't become a drunken idiot at 11 o'clock that night" of Panas' death, Binns argued, echoing the term lawyers for the city used to describe Tepper in their opening argument. "The city knew that he was a drunken idiot for the entirety of his career."

Binns cited statements from 10 witnesses at the shooting scene who said Tepper identified himself as a police officer or flashed his badge on the night he shot Panas.

Mark Maguire, a deputy city solicitor, argued that most of those witnesses were Tepper's relatives, people with incentive to portray the shooting as a self-defense by an officer doing his job.

Maguire noted that nine other witnesses who were in the crowd of young men gave statements in which they said they did not recall Tepper identifying himself as an officer.

According to Maguire, Tepper had just seven citizen complaints over 16 years on the force - a relatively small number - and none in the seven years before Panas' was killed.

"Nothing about that says he's a problem officer," Maguire told jurors. "Nothing about that says he's likely to commit murder."

Tepper was drunk, off-duty, and out of uniform when he grabbed his personal gun and stormed outside his house, Maguire said. He wasn't arresting anyone, trying to prevent a crime, preserve the peace or protect property or a person - in other words, not acting as a police officer, he said.

Maguire called the killing a senseless tragedy but reminded jurors their decision can't be guided by sympathy.

"What Mr. and Mrs. Panas want is impossible for anyone to give them," he told jurors. "What they are asking you to do isn't allowable under the law."

Contact John P. Martin at 215-925-2649, at jmartin@phillynews.com, or @JPMartinInky on Twitter.