San Antonio police arrested a father and son late Wednesday in connection with the headline-grabbing shooting deaths of pregnant 18-year-old Savanah Soto and her boyfriend Matthew Guerra, 22. Christopher Preciado, 19, has been charged with capital murder in the deaths of Soto and Guerra, Sgt. Washington Moscoso said during a press conference at San Antonio Police Department headquarters. Police believe Preciado killed the couple during a “drug deal gone bad” and later called his father, Ramon Preciado, 53, to help dispose of the bodies, according to Moscoso.