CLAYTON, Mo. (AP) — An internal investigation by St. Louis County police has resulted in written reprimands for 11 officers assigned to patrol the region’s light rail system.

Police announced the reprimands on Friday following a 16-week investigation. Some of the reprimands are for loitering in security offices for MetroLink, while others are for covering security cameras inside those offices.

But police say other allegations of misconduct were unfounded or not substantiated.

County Police Chief Jon Belmar began the investigation in July following reports by St. Louis Post-Dispatch columnist Tony Messenger. Names of the reprimanded officers have not been disclosed.