The suspect has been identified as 30-year-old Jonathan Wesley Harris of Johnstown, Pennsylvania.
Harris is charged with first, second, and third-degree murder, robbery and theft.
He was arrested by the U.S. Marshals while getting off a bus in Pittsburgh on Wednesday after allegedly fleeing the Philadelphia area.
Sources said after learning of his departure from Philadelphia to Pittsburgh on a bus that was due to arrive at 3:45 p.m., undercover agents waited until he got off the bus and took him into custody without incident.
Court records show Harris, from Johnstown, Pennsylvania, had just been released from state prison on July 15. He was serving time on a list of charges including assault. Officials said he was staying with a sister in southwest Philadelphia.
Authorities say he was the person of interest seen in the surveillance images released earlier this week.
An anonymous source called police after seeing the video on news reports, authorities say.
According to authorities, this person said Harris texted him or her around the time the former Playboy model was murdered and said he was at her apartment in Ardmore.
In a news conference held Wednesday afternoon, Montgomery County District Attorney Kevin Steele said Kraft died a violent death.
"Christina was beaten, and the beating was substantial. Her nose was broken, she had black eyes, there was a lot of blood," he said. "Then she died of strangulation. Something was put around her neck."
According to investigators, Kraft left her apartment on Sibley Avenue in the early morning hours of Wednesday, Aug. 22 and used Lyft to go to the 1400 block of Chestnut Street in Center City Philadelphia.
Surveillance video showed Kraft meeting with Harris near South Broad and 13th streets, the D.A. said. A short time later, the two enter a vehicle.
According to investigators, records indicate the front door of the apartment opened at 3:08 a.m. and the back door leading to a terrace was closed at 5:19 a.m.
Kraft was killed during a violent struggle within that two-hour timespan, Steele said.
Kraft's body was discovered on the evening of Aug. 22 during a wellness check by police.
Steele said he has not seen anything to indicate there was a previous relationship between Harris and Kraft, but he added the investigation is still ongoing.
"Whether it was a chance meeting or something else, I can't say," said Steele.
Meanwhile, police are also looking for 31-year-old Andre Melton in connection with a burglary at Kraft's apartment the previous weekend.
Investigators say designer bags and jewelry Kraft reported stolen were found at his Theodore Street home in southwest Philadelphia. Steele said investigators do not yet know if this burglary and Kraft's murder are connected.
Kraft was a model who, according to a booking page, credits herself with a "tasteful photo shoot for Playboy that was beyond Hollywood glamour."
Her profile also lists photo shoots for Vanity Fair, Victoria's Secret, and Maxim.
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