The 16-year-old male wanted for knocking out a 60-year-old SEPTA rider on the 15th Street Market-Frankford El platform on Monday will turn himself into police on Thursday, officials said.

SEPTA officials said late Wednesday that SEPTA police are working out the arrangements with the 16-year-old's attorney.

Thomas J. Nestel III, SEPTA's police chief, said Tuesday that the incident started inside an El train car headed to Center City and escalated into the attack that happened at 3:15 p.m.

SEPTA police released video of the incident with the hope of identifying the parties involved.

With help from two tipsters, along with facial-recognition software, police were able to put together a warrant for the teen's arrest.

The District Attorney's Office approved a warrant for the teen's arrest Wednesday night, and the teen's attorney began negotiating the terms of surrender.