Thirty-seven-year-old Byron Allen is charged with first-degree murder and other offenses in the September 2016 killing of Natasha Gibson.
As first reported by Action News' Chad Pradelli, Allen had been considered a person of interest in Gibson's murder since the beginning of December.
Allen has already been charged in connection with four violent sexual assaults against women in the Kensington section of Philadelphia.
The mother of a 10-year-old girl, Gibson was killed as she walked home from a bar to a friend's house on Baily Street in Yeadon last September.
"He did take her belongings, he did take her pocketbook, he did take her ID, but that wasn't the motive for this crime. This is a heinous, brutal murder, and the motive is the stalking in night just to kill," said District Attorney Jack Whelan (R-Delaware County). "The sport of killing is the motive."
Prosecutors say she was stabbed more than 20 times, and that the killing was a random attack.
"We know he killed her by way of slashing her. Over 20 stab wounds to her body, multiple stab wounds to her chest, her face, her neck. Her neck was slashed open," said Whelan.
Police say Allen was cut during the attack, and trailed his own blood for almost 2 miles, from the crime scene in Delaware County up to Baltimore Avenue, over to Philadelphia where the murder knife was discovered in a storm drain at 61st Street, and then to a convenience store at 58th and Catherine where a surveillance video showed Allen calmly buying a beer.
DNA testing results ultimately led investigators to Allen.
At a news conference Wednesday, Philadelphia police released details about the violent sex assaults in Kensington with which Allen has already been charged.
The first attack happened on April 19, 2016, at Braddock and Toronto Streets, where a 45-year-old woman had her throat slashed. She later recovered.
"A 45-year-old female was assaulted by our offender, who slashed her throat with a box cutter. The slashing was so severe it severed her vocal chords and her trachea," said Capt. Mark Burgmann, Philadelphia Special Victims Unit.
On July 12, 2016, on the 3800 block of Jasper Street, a 24-year-old woman was beaten and choked unconscious.
In late July 2016, on the 3100 block Jasper Street, a 36-year-old woman was choked unconscious and sexually assaulted.
And on Oct. 1, 2016, on the 2700 block of Ruth Street, a 23-year-old woman was choked unconscious and sexually assaulted.
Police say they received numerous tips after releasing surveillance video in connection with the attacks.
Those tips, they say, eventually led them to Allen.
He is currently behind bars in Philadelphia, charged in connection with all four Kensington assaults.
Capt. Burgmann said Allen is still a suspect in the murder of Rickie Morgan, a woman whose body was found last July 16, only blocks from where the four other Kensington attacks occurred.
"He's the prime suspect in that one," said Burgmann.