Police announced Monday morning that Charlie Samuel of Los Angeles is being held without bail at a downtown Los Angeles jail.
Officials say the body of high school student Lily Burk was found in her black Volvo on Saturday and that she appeared to have head injuries.
Police say Burk is believed to have been the victim of a botched robbery.
"It's an unbelievable, incomprehensible shame that a life should be just cut out or snuffed out like that," Glenn Harcourt, one of Burk's teachers, told CBS News station KCBS Sunday. "She was just a wonderful, vibrant, beautiful kid."
No other details surrounding Samuel's arrest have been released.
Family friends say Burk was about to begin her senior year at Oakwood School in North Hollywood.