Male suspect sought after punching woman in Philadelphia store

12 articles · Updated · Fox News · May 7

Philadelphia police released surveillance footage from an April 22 attack around 11pm at a convenience store on the 4000 block of Market Street in University City near UPenn.
Police said a verbal argument escalated after the man spat on the woman, then tackled and repeatedly punched her, leaving her injured before fleeing with another person.
Bystanders and a store employee were unable to stop the assault, and authorities said the suspect wore black clothing and an Eagles-logo hat while the victim received advocacy support.

Philadelphia's murder rate is at a 60-year low, so why do brutal public assaults remain a common threat?

If bystander intervention is the norm, why did the efforts of three people fail to stop this violent attack?