It happened around 7:30 p.m. Sunday near 12th and South streets.
Investigators say the 25-year-old father was getting out of his car when he was approached by a man he did not know.
They say the gunman then shot the victim once in the neck in front of his children and a woman.
There is no word of a struggle, or even an argument, between the suspect and victim.
The family of four ran to a nearby vape shop for help. A book bag belonging to one of the children was left on the street.
The father was taken to Jefferson University Hospital and is in stable condition.
The gunman remains on the loose.
Anyone with any information is asked to call police at 215-686-TIPS.
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