He held a small army of police at bay for more than 4 hours after, investigators say, he shot his ex-girlfriend, identified as 38-year-old Patty McNally.
Police say she had several restraining orders against Osborne.
Police say Osborne shot his ex as she sat in her minivan in 3200 block of Rawle.
She died of a gunshot wound to the chest.
Investigators tell Action News Osborne then made a run for it, to the home of acquaintance Tom Donnelly a few blocks away on Magee.
"I wasn't even home," said Donnelly who's two teenage sons were at home. "He ran in there and he still had the gun."
"I looked in his hand and saw he had the gun wrapped in a t-shirt," said Donnelly's son William Santana. "He was just wandering around the house crying and all upset. I told him he had to leave!"
A few minutes later, Donnelly arrived at home.
"He was crying, saying 'please don't tell the cops, please don't tell the cops.'" Donnelly said. "I said to him, 'What did you do?' and he said 'I shot her."
SWAT team negotiators converged on the apartment in the 3200 block of Magee, trying to talk the suspect into surrendering.
They brought in his parents and a longtime friend to try to talk him out, but to no avail.
Just before 10pm a high powered SWAT team moved in, only to find the suspect had taken his own life.
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