Lou Hartdegen, 75, allegedly beat, suffocated and strangled Judith, his wife of 53 years, Monday and then set up a crime scene and implicated a 26-year-old neighbor to throw police off-track, philly.com reported Wednesday.
Police said they questioned the neighbor for several hours Monday, then released him.
Hartdegen "did a lot of things trying to outsmart homicide detectives, Philadelphia police Capt. James Clark said.
"It is very troubling that he picked out the wrong person" to try to cover up the crime," Clark said.
The killing occurred after some kind of "domestic argument" between the couple, said Clark.
Lou Hartdegen remained hospitalized Wednesday morning, having suffered injuries during the incident. He was charged at the hospital and was to be held without bail.
Police said Hartdegen later admitted to the killing.
Police were called the Hartdegens' apartment above a storefront shortly before 2:30 a.m. Monday, whereupon Judith Hartdegen was pronounced dead at the scene.
Investigators originally thought someone had broken in through a rear window of the apartment and attacked the couple.