A 17-year-old taken into police custody Wednesday is expected to be charged in the stabbing death of his foster mother, who was found slain in the bathtub of her East Germantown home, and the slaying of a 20-year-old acquaintance whose body was found in a duffel bag behind a home in West Philadelphia, a law enforcement source told The Inquirer.

The source, who requested anonymity to discuss an ongoing investigation, said investigators believe the teen met his victims as he moved between foster homes in recent weeks.

The killings were discovered amid an unusual stretch of violence in the city, with 19 homicides reported through the first 14 days of the year. Several more deaths were recorded Wednesday.

The teen, whose name The Inquirer is withholding because he has not been formally charged, was taken into custody Wednesday morning after he and three other teenagers crashed his foster mother’s car in West Philadelphia, Homicide Capt. Jason Smith said at a news conference. Renee Gilyard, 64, had been the teen’s foster mother for just three days, Smith said. She also was the mother of a Philadelphia police officer.

Capt. Mark Burgmann of the Special Victims Unit said police had recently interviewed Gilyard’s foster son about the disappearance of Jimmy Mao, 20, of Southwest Philadelphia, because police believed he was the last person to see Mao before Mao went missing from the 5800 block of Angora Terrace.

Just before 5 p.m. Wednesday, police said they found a body inside a duffel bag around the corner from there, on the 1000 block of Cobbs Creek Parkway. Law enforcement sources said the body was that of Mao.

Burgmann did not say when police interviewed Gilyard’s foster son, but did say that on Jan. 7 Mao’s disappearance was reclassified as a kidnapping case because Mao’s brother began receiving text messages demanding a ransom for his return. Burgmann said that police did not find the nature of the demands credible, but that the case remains under investigation.

In addition, Burgmann said another teen was missing: Jacob Merritt-Richburg, 16, of North Philadelphia, whom Burgmann called an acquaintance of Mao’s, and whom he said had been missing since Jan. 6.

“We’re very concerned with the safety and well-being of both” Mao and Merritt-Richburg, Burgmann said Wednesday morning.

In Gilyard’s slaying, Smith said, relatives had tried to contact her during the day Tuesday and grew concerned when they did not hear from her. Officers who responded to her home on the 300 block of Mechanic Street about 1:20 a.m. Wednesday initially found the door of the first-floor bathroom locked. After opening the door, Smith said, officers found Gilyard inside covered in blood and partially in the tub.

Gilyard had been stabbed twice in the left neck and had suffered defensive wounds to her hands, Smith said. Gilyard’s car, a black Nissan Rogue, and cell phone were missing, and her purse had been emptied onto the bed.

Her foster son was not home, Smith said.

Police broadcast an alert for the victim’s car and later spotted it in West Philadelphia. After a chase, the car crashed on the 4300 block of Sansom Street around 10:30 a.m. Inside the vehicle, police found the foster child, a teenage boy, and two teenage girls.

A black Nissan Rogue crashed into the back of a truck on the 4300 block of Sansom. Four males were taken into custody after they crashed a car after a chase. The vehicle belonged to Renee Gilyard, the 64-year-old mother of a Philadelphia police officer. She was found stabbed to death early Wednesday in a bathtub in her East Germantown home.
DAVID MAIALETTI / Staff Photographer
A black Nissan Rogue crashed into the back of a truck on the 4300 block of Sansom. Four males were taken into custody after they crashed a car after a chase. The vehicle belonged to Renee Gilyard, the 64-year-old mother of a Philadelphia police officer. She was found stabbed to death early Wednesday in a bathtub in her East Germantown home.

Smith did not identify the other teens, and did not say whether any other evidence relevant to the homicide was found inside the SUV.

Police said Merritt-Richburg was not in the car.

Burgmann said Mao was last seen Dec. 29 on the 5800 block of Angora Terrace. The interview of Gilyard’s foster son regarding Mao’s whereabouts did not yield useful information, he said.

During the investigation into Mao’s disappearance, Burgmann said, Merritt-Richburg also was reported missing. Burgmann said police believe Merritt-Richburg knew Mao somehow, and “may be in possession of some property that belongs to Jimmy Mao,” though he declined to offer specifics.

Before Mao’s body was discovered, Burgmann declined to say if he believed either Mao or Merritt-Richburg was still alive.

Any answer he might give, he said, "would be pure speculation on my part.”

Staff writer Joseph A. Gambardello contributed to this article.