Philadelphia's district attorney announced Thursday that his office is helping police investigate a controversial and still-fuzzy incident that a high school sophomore said landed him in the hospital.

Darrin Manning, 16, maintains that a female police officer sexually assaulted him during a pedestrian stop on Jan. 7 near the corner of Broad Street and Girard Avenue.

Manning has said that, while being frisked, the officer grabbed his genitals so forcefully that one of his testicles ruptured, sending him to a hospital for surgery.

The alleged brutality reportedly occurred right after Manning was arrested.

Manning and his teammates – on their way to a basketball game – allegedly fled the area after a police officer approached them. Video surveillance reportedly shows that Manning struggled with officers after he stopped running.

Why Manning was stopped and what exactly happened after his arrest, however, remain unclear.

During a Thursday afternoon press conference, District Attorney Seth Williams and Police Commissioner Charles Ramsey said they are working together to change that.

"To gather as much evidence, to get in touch with and get statements from as many witnesses, to get medical records, documents, videotapes, everything we can so that we can find out the truth of what happened that day," said Williams.

Williams did not rule out the possibility of his office using a grand jury to help with the fact-finding effort.

Typically, the district attorney's office does not start its investigation until the police department's Internal Affairs Bureau has wrapped up its probe.

To date, however, police have not been able to meet with Manning, his lawyer or any possible witnesses.

Lewis Small, Manning's attorney, has refused Ramsey's request to meet with him and Manning to discuss the incident. That led, in part, to the district attorney getting involved earlier than usual.

"The reason we're doing this is so we can have a comprehensive, complete investigation. Get the information that we need, a determination based on real facts, not just the word fact, but actual evidence," said Ramsey.

On Thursday, Small said he's pleased Williams' office is now involved with the investigation and that Manning and other witnesses are "happy to cooperate" with prosecutors.

"It's a much better way to get to the truth," said Small of the joint investigation. "It's very difficult for police to investigate police."

Manning, who attends Mathematics, Civics and Sciences Charter School, has been charged with three misdemeanors: simple assault, reckless endangerment of another person and resisting arrest.

He's scheduled to appear in Family Court on March 4.

The officer in question, whose identity has not been released, is currently on administrative duty.