Jimmy Mao

PHILADELPHIA -- Police in Philadelphia arrested a 17-year-old boy in connection with the murders of his foster mother and a man found dead inside a duffel bag.Xavier Johnson was charged in the stabbing death of 64-year-old Renee Gilyard and the killing of 20-year-old Jimmy Mao, who "were brutally tortured and murdered," according to police.Gilyard's body was discovered with multiple stab wounds in a bathtub inside her Philadelphia home Wednesday. Gilyard was also the mother of a Philadelphia police officer.Police said the contents of her purse had been dumped out and her SUV was gone.The SUV was later found when it crashed into a tree and caught fire in West Philadelphia, and inside the SUV were four teens, including Johnson. He had been placed in her care just three days earlier.Johnson is also charged in the death of 20-year-old Jimmy Mao, who was previously placed in the same foster home. Police said Mao's family has been receiving ransom texts since his disappearance.Mao's remains were found Wednesday night inside a duffel bag thrown down a hill and into a back alley. It was not clear when Mao was killed.Seventeen-year-old Jacob Merritt-Richburg, who police said is an acquaintance of Mao, has also been reported missing. It is not clear if Johnson is connected to Merritt-Richburg's disappearance.Police said Johnson has five previous arrests.