UPDATED: 6:30 p.m.
A source from inside the facility told KYW Newsradio that the gunman was the ex-boyfriend of one of the women he held hostage.
The source added that the armed man came through a security guard station around 8:30 a.m., and there was some kind of altercation. During that confrontation, the guard tripped a panic button, alerting day-shift employees of an emergency, which summoned police.
Fiore says a police hostage negotiating team tried to resolve the situation through contact with the man over the phone. But the Attorney General's office says the shooting happened when the gunman and hostages exited the building. Fiore says the gunman did not surrender, leading the SWAT team to “intervene.”
"He walked in through the main entrance and he grabbed his girlfriend and started punching her and he said, 'I have nothing to lose,' " he recalled. "And he pulled a gun and shot in the air."
Several relatives of the gunman were kept away from reporters, who were about a half-mile from the UPS building. An unidentified woman, who said she is the gunman’s niece, said she knew he'd had a relationship with a worker there.
"Nobody seen this coming. Nobody in our family seen this coming. This came out of nowhere," she said. "Right now, I’m scared."
The lockdown was lifted at 12:30 p.m.