The suspect accused in a two-state killing spree has pleaded guilty.

Nicholas Sheley was already serving six life sentences for killing six people in Illinois. Wednesday, he pleaded guilty to killing an Arkansas couple at a Festus hotel in 2008.

Police say Sheley attacked and killed Jill and Tom Estes outside the hotel. Police say they were random victims.

Prosecutors say his killing spree began in June 2008. They arrested him the next month.