COLUMBIA, Mo. -

A man who admitted to robbing a Columbia convenience store will spend the next two decades behind bars.

Chadwick Simmons, 23, was sentenced Monday to 22 years in jail for robbing a Break Time in Columbia. Officials say he robbed the Nebraska Ave. store on Dec. 26.

Simmons received 15 years for a second-degree robbery charge and seven years for an unrelated burglary charge.

He is already serving a nine-year prison sentence for drugs at the Jefferson City Correctional Center.