A 17-year-old boy fatally shot by a police officer in East Pittsburgh seconds after he fled a traffic stop did not pose a threat to anyone, a lawyer for the family of the teen said.The East Pittsburgh police officer who fatally shot 17-year-old Antwon Rose during a traffic stop spoke with Pittsburgh's Action News 4 reporter Marcie Cipriani in person Thursday. Michael Rosfeld said he and his family are trying to deal with what happened. He said this is a difficult time for them and said he wasn't ready to talk about what happened in the moments before he fired his gun or why he did it. Civil rights attorney S. Lee Merritt said late Wednesday that he doesn't see any apparent justification for the use of deadly force by an East Pittsburgh police officer that left Antwon Rose Jr. dead. Allegheny County police are conducting an independent investigation of the shooting in East Pittsburgh.Part of the encounter was captured on video and posted to Facebook by a bystander.Rosfeld said he has stayed away from news coverage and that he was unaware video of the shooting existed or that there have been protests surrounding the shooting.Video: Police open fire during traffic stop believed to be connected to earlier shootingThe shooting has sparked some social media outrage and calls for punishment of the officer, including from rapper Nas and a handful of other celebrities. A Wednesday night protest at the East Pittsburgh police headquarters lasted for several hours and drew more than 100 people, some of whom laid down in front of a police cruiser.A second protest Thursday afternoon at the Allegheny County courthouse attracted nearly 1,000 people, including speakers decrying police use of force and gun violence.Investigators said the officer stopped the car Antwon and two other people were riding in Tuesday because it matched the description of a car reported to be involved in a shooting about 15 minutes earlier in a nearby town. As the officer took the driver into custody, the short video shows Antwon and the other passenger running from the car.News conference: Teenager shot, killed by police in East PittsburghThe officer quickly fired three shots, all of which struck Antwon, who later died at a hospital from his injuries. The medical examiner has not said where the teen was struck."We must emphasize that rumors of (Antwon) being involved in a separate shooting are unsubstantiated," Merritt wrote in his statement, saying the use of deadly force seems unjustified. "We know that he was not armed at the time he was shot down, that he posed no immediate threat to anyone."Antwon's friends, family and teachers said he was a promising student, who volunteered at a charity, was generous and had a "million-dollar smile."Allegheny County Police Commissioner Coleman McDonough said Wednesday that he is confident the car Antwon was in was involved in the earlier shooting, partly because a window had been shot. He said officers found two guns in the car, and that the driver was released after questioning without being charged.McDonough confirmed that Antwon was not armed and that no shots were fired at the officers.Pennsylvania law allows officers to use deadly force against a fleeing suspect in only a handful of circumstances. It's permitted if the suspect poses a threat of immediate danger, has used or threatened lethal violence previously or possesses a lethal weapon.Leaders of the Pittsburgh-based Black Political Empowerment Project asked Thursday for the Pennsylvania attorney general's office to investigate this and other police-involved shootings, citing only two instances where the Allegheny County district attorney has filed homicide charges against police officers in fatal shootings in the last 20 years.A joint statement from East Pittsburgh officials and police issued Thursday expressed condolences and sadness over Rose's death and asked the community to respect the investigative process.Democratic U.S. Sen. Bob Casey also issued a statement Thursday saying the teen's family has a right to answers."I am disturbed by what I saw on the video, and I have numerous questions about exactly what happened and why," he said.The Associated Press contributed to this article.