It also acquitted Sean Cahill, 34, of making a false statement to the FBI. When the foreman announced the verdicts, the wives of both Harvey and Cahill wept. Harvey showed no reaction; Cahill smiled.
Jurors approached by a reporter afterward would not comment.
Their verdicts likely were based on credibility issues and on discrepancies in testimonies by government witnesses. Harvey's accuser was a 21-year-old drug addict who was high on cocaine and heroin on Oct. 8, 2009, when the alleged offense occurred.
James Funt, Harvey's attorney, said afterward that Harvey "was grateful that the jury saw the case for what it was."
Asked if Harvey would seek to get his police job back, Funt said: "Tonight, he just wants to be with his family, and [he] will make those decisions at a further time."
Fortunato "Fred" Perri Jr., Cahill's attorney, said: "Sean and his family are obviously thrilled" by the verdict. He said Cahill would try to get his police job back.
In his closing argument yesterday, Funt told jurors that Harvey's account of what happened was credible because it was backed by Cahill and because it had the "ring of truth."
Harvey testified that between 6 and 7 p.m. Oct. 8, 2009, he saw the woman and went to talk to her. She took him to a house on D Street near Kensington Avenue, claiming that there would be a drug stash in the house later that night, Harvey said.
In the house, the two flirted, Harvey said. He said she began touching herself, then he masturbated and ejaculated. A DNA analysis of semen on the woman's jeans, which were lying next to her, found that it was Harvey's.
The government, however, contended that the encounter between the two happened later that night.
In her closing argument, Assistant U.S. Attorney Michelle Morgan called Harvey's version of events a "fairy tale."
"It's as if he sat down and concocted a story to explain how his DNA got on her pants," she said.
What really happened that night inside the house, based on the woman's testimony, Morgan said, was this: The woman and her male friend were sitting naked on a mattress in a bedroom of that house, injecting drugs, when police burst in looking for drugs. While her friend was escorted out of the room, the woman was left alone with Harvey.
"He closed the door," Morgan said. "He said, 'Spread your legs,' and he shined a flashlight between her legs and he took his penis out. He masturbated and he ejaculated." The woman and her friend called 9-1-1 to report the incident that night. Her voice was "shaking," Morgan said.
Two cops, Hayden Smith and Curt McKee, testified that they had gone to the house with Harvey. According to trial evidence, they had gone about 10:30 p.m.
Harvey agreed that he went back to the house about that time. He said Cahill was there, too. But McKee and Smith both testified that Cahill was not at the house.
Last April, Cahill told the FBI that he was at the house and that Harvey was never alone with the woman.
Perri, in his closing argument, pointed out that the day after the incident, the woman told police that "three white males" went into the bedroom. The defense contended that the three white officers were Harvey, Cahill and McKee. (Smith is black.)
Harvey previously was charged in state court before the feds took the case. But in May 2012, Common Pleas Judge Barbara McDermott dismissed the case, ruling that the District Attorney's Office took too long to prosecute Harvey. The D.A.'s office has an appeal before the state Supreme Court. Funt said the Supreme Court has not decided whether it will take on the appeal.
On Twitter: @julieshawphilly