Many of the crimes are what has become known as "Apple picking," when thieves grab smart phones out of the hands of unsuspecting owners.
A suspect in a rash of such crimes is 19-year-old Benjamin Teague.
"We have several warrants for Mr. Teague for snatching cell phones," Chief Thomas Nestel said. "He has a propensity for violence."
Investigators say Teague frequents the north end of the Broad Street Line, and targets female riders.
"Sometimes our female victims resist and, when resisting, he uses force to take their cell phones," Nestel said.
On his account, Nestel tweeted Teague's picture and, in 17 words, he calls out the suspect, telling him every transit cop has his picture.
He concluded by saying "I hope you like cheese sandwiches," a reference to jail food.
"Cheese sandwiches are the staple diet for those incarcerated in the Philadelphia system. We provide a beautiful 2 ounce American cheese sandwich, so I just want to prepare him for that," Nestel said.
To follow Chief Nestel on Twitter, follow this link to his Twitter page.