Was stolen from a fellow police officer three years earlier.
Philadelphia police officer Leon Pearson told investigators he fell asleep while drunk in his home, then woke up to find his gun missing.
He also said there was no sign of forced entry and nothing else was missing.
That gun ended up in the hands of Edward Archer who used it to shoot Philadelphia police officer Jesse Hartnett as he was driving his patrol car on January 7.
Archer, 30, fired 13 times, striking Hartnett three times in the arm. But the officer managed to step out of his car and chase him down, shooting him in the buttocks.
Archer, who was wearing a white thawb (Muslim robe), survived the shooting.
At the hospital, he told police he had sworn allegiance to ISIS, but his mother said he suffered from mental illness.
Police, of course, said this was just the latest chapter in the War on Police. And although they did say the gun was stolen from an officer, they did not provide details.
Pearson did not report the gun stolen for 48 hours instead of the required 24 hours by departmental policy, so he was disciplined for that.
In October 2013, Pearson told police he was at his home in Overbrook when he fell asleep, drunk, and awakened to find his gun gone. Nothing else was taken from the house, he said, and there were no signs of forced entry.
Somehow, nearly three years later, his gun made its way into the hands of Edward Archer, who used it to shoot Hartnett at point-blank range as the officer sat alone in his patrol car in West Philadelphia, authorities said.
Pearson, in a brief interview, declined to discuss the reported theft of his gun and said he had no idea it was later used to shoot a fellow officer.
“I don’t know nothing about it,” he said. “They didn’t tell me about it.”
Police said Pearson was disciplined for not reporting the gun missing during the required 24 hours, but did not elaborate how he was disciplined.