What was left to do was figure out what happened and why it happened.



Glenn was carrying a white, sealed envelope that read "Doomed People" on it, Ross said.



The commissioner said police found a "rambling" letter allegedly written by the gunman in which he expressed hatred toward police and probation officers. He said there was no reason to believe at this point that the gunman had any religious beliefs that drove him to the shootings.



Other than his "rantings in that letter," Ross said Glenn's motive was unclear. "We may never know."



Employees at the Central City Toyota dealership, whose back end faces Sansom Street, said on Saturday that Glenn had ducked underneath a partially opened garage door there to hide from police at one point during the rampage.



The dealership's cleaning crew, the only people in the building at the time, spotted him hiding among the tires, the employees said. Glenn apparently did not see them. He then fled out a back door.



Police would later corner him in an alley a few yards down the block.



Ross said Glenn "has a pretty significant past" and was well known to police.



According to court records, Glenn had a history of drug-possession convictions in Philadelphia. He had also been arrested and charged in connection with a gang-related rape in a November 2009 incident, but these charges were later dropped.



On the night of Nov. 19, 2009, a 24-year-old woman had allegedly been accosted by six men near 56th and Walnut Streets after she had gone out to get takeout food. She was allegedly forced into a nearby apartment building and raped. The woman had been treated and released at Episcopal Hospital.



Court records show prosecutors dropped charges against Glenn in the rape case in December 2011. It was not clear why. Lawyers who had been involved in the case did not return calls for comment Saturday. A person who previously knew Glenn, Deedee Griffin, 22, of North Philadelphia, contended charges were dropped because there was evidence that the victim was not forced into the encounter.