Anyone who recognizes the suspect in the above photo is urged to contact Philadelphia Police at 215-686-TIPS (8477) or visit the Police Department's website.
In addition to the pictured suspect, police say they are also looking for a getaway driver. No description of that person was available.
Meanwhile, police say the would-be robber who was killed had escaped from the Curran Fromhold Correctional Facility several days before the attempted robbery of William Glatz Jewelers on Thursday.
Deputy Commissioner William Blackburn on Friday identified the dead suspect as 22-year-old Kevin Turner. Police say Turner was fatally shot in a gun battle with the store owner, 67-year-old William Glatz, who also died.
Police added that Turner was the one who fired the shot that killed Glatz, but they were still trying to deteremine who fired the shot that killed Turner: Glatz, another worker, or both.
The other employees in the store, who were not injured, told police the two men had been in the store and "mingled around the premises" several times in the days before the holdup, Blackburn said.
Investigators also believe the men committed at least one other robbery nearby on Monday. In that case, jewelry store employees were bound with duct tape and robbed of about $2,400 in cash and jewelry, Blackburn said.
Blackburn says Turner had a long arrest record that included mostly drug and weapons charges. He says Turner escaped from a prison in Philadelphia on Oct. 12.
Police and prison officials were trying to determine how Turner, who been held at the prison since March on weapons charges and a burglary case, broke out of the Northeast Philadelphia prison.
He was being sought since he disappeared sometime between two early-morning head counts, prison officials said.
Turner was arrested after an off-duty police officer in a pizzeria reported overhearing Turner discussing plans for a robbery, Blackburn said. On-duty officers responded and pulled over his car, where they found masks, gloves, duct tape and two guns, Blackburn said.
He said authorities have interviewed family and friends but have not determined where Turner had been hiding out since his escape.
People in the close-knit working-class neighborhood said Glatz's store was a fixture for as long as they could remember. Though the family moved to suburban Bucks County several years ago, Glatz enjoyed returning to the old neighborhood and his longtime customers, said Charles McKeown, a former neighbor whose family also ran a business down the street for decades.
"His father had the store before him. Everybody knew the family," said McKeown, who now lives in suburban Cheltenham Township. He came to the scene of the shooting after getting word of Glatz's death while he was attending a funeral.
"He was quiet, meek, mild. Just a gentleman," McKeown said. "He loved his job."
The Associated Press contributed to this report.