Officers' knocks initially went unanswered, but before they had to force entry a woman came running out of the front door of the home, police said.
While she tried to tell police what was going on, gunfire erupted at the rear of the home, Amaro said.
The suspect, who was later identified as Frank McQueen, allegedly shot at police, who then returned fire. McQueen and Officer Matthew Stewart were both struck, with Stewart being hit in his abdomen, just below his bulletproof vest.
Stewart, a nine-year veteran, was treated for his injuries and released before noon.
McQueen, 34, of 17th near Westmont in North Philadelphia, died at the hospital.
At a news conference, Chester Police Commissioner Joseph Bail Jr. said McQueen had a long history with police, including arrests in Philadelphia, Delaware County and Camden.
Police said McQueen was arrested for violating a protection-from-abuse order at the same house in Chester on May 15, but he made bail last week.
"My personal feeling is these protection-from-abuse [orders] are only a piece of paper," Bail told reporters. "How do you protect a woman from a piece of paper?"
The shooting was just the latest in a string of violent incidents in Chester, which announced on May 6 that it was going to flood its streets with extra police power under what officials called "Operation City Surge."
On May 1, the body of Dino Dizdarevic, 25 a Bosnian immigrant who had moved to Philadelphia from Louisville, Ky., was found beaten to death in a Chester alleyway. His slaying remains unsolved.
Chester Mayor John Linder's wife was carjacked at gunpoint in front of their home on May 15. The incident is believed to have been random and the mayor's wife, Deana Linder, was not hurt.
Back on April 14, Nick DiGregorio, 66, a Vietnam veteran and former cop, was shot in the face by a stray bullet that pierced his windshield as he drove down 9th Street near Pennell in broad daylight. DiGregorio survived, but the bullet remains lodged in his left cheek.
At the beginning of May, Delaware County District Attorney Jack Whelan said that the city of 34,000 had already marked 11 homicides in 2014, which was double what the tally was at the same time last year. By the end of the month, Chester had marked 13 slayings.
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