INDEPENDENCE, MO. ? The number of people charged with the killing of a Kansas City Symphony bass player has grown to four.

Jonathan Box, 17, of Lee’s Summit, faces one count each of second-degree murder and armed criminal action in the death of 51-year-old Steven Peters, Jackson County Prosecutor Mike Sanders announced Thursday.

Three other men face the same charges – Sylvon Sese, 20, of Independence; and Richard D. Jones, 21, and Michael A. Jones, 17, who aren’t related and live in Kansas City.

Sanders said in a news release that he doesn’t believe additional suspects will be charged in the killing.

Box told police that he planned last week’s robbery, according to the probable cause statement. He said the men planned to tie up Peters and steal the military-type firearms that reputedly were inside.

But Box told police that Peters greeted the men with a handgun when they broke into his duplex, and shots were fired. The men fled and took Richard Jones, who was shot in the arm, to the hospital, according to the probable cause statement.