Two more people have been arrested after a Mississippi police officer was gunned down outside his police station.

Harrison County Sheriff Troy Peterson tells WLOX-TV both men were arrested Wednesday on charges of accessory after the fact in the capital murder case.

Twenty-year-old Dalentez Brice and 21-year-old Joshua Kovach are being held without bond. It wasn’t immediately known whether they have lawyers who could be reached for comment.

Veteran Biloxi police Patrolman Robert McKeithen was shot several times in the back Sunday in the police station parking lot.

Nineteen-year-old Darian Atkinson is accused of killing him.

Atkinson’s 21-year-old brother, Davian Atkinson, is also charged as an accessory after the fact. Authorities say he drove his brother to Wiggins after the killing and let him make phone calls.