PITTSBURGH — Pittsburgh police have filed a homicide charge against a Pittsburgh man, claiming he fired the shot that killed Zachary Sheridan, 24, of Pittsburgh early Saturday morning.

Sheridan left Slippery Rock University in 2011, where he was a standout defensive player on the football team.

Isiah Smith, 22, was in custody over the weekend when he turned himself in to police. However, at that time authorities released him after the Allegheny County District Attorney's office would not approve the filing of charges.

But police Monday morning went ahead and filed charges against Smith of criminal homicide, aggravate assault and recklessly endangering another person. He is in the Allegheny County Jail.

Sheridan of Brookline was involved in a fight outside the Original Hot Dog Shop. Two groups got into an argument outside the restaurant. Sheridan and his friends walked away and the other group followed. Sheridan was shot once several blocks away.

A four-year football starter, Sheridan led The Rock in tackles in each of his final three seasons. He was a team captain.

SRU players will wear a decal with Sheridan's uniform No. 4 on their helmets this season.

Sheridan will be buried Wednesday morning.

Mike Manko, a spokesman for the district attorney's office, declined to discuss specific details about what changed between Saturday and Monday that convinced prosecutors to go ahead with charging Smith.

Manko said that it is not uncommon in certain felony cases for police to submit a first draft of an affidavit only to have the district attorney ask police to get more information.