HOUSTON, Texas (KTRK) -- Two juveniles are facing murder charges in the killing of a 61-year-old man in northwest Harris County.The Harris County Sheriff's Office announced the arrests of a 13-year-old boy and a 15-year-old girl on Tuesday night.Investigators said the juveniles allegedly killed a man for his white Nissan on February 8, in the 5600 block of Hardwood Forest Drive, near Antoine.Howard Boston was found dead in the front yard of his home, according to investigators.Authorities said his vehicle was found abandoned a short time later at the Garden City Apartments on West Montgomery.Both suspects are now being held at the Harris County Juvenile detention center on capital murder charges.