RALEIGH, N.C. (AP) — The younger brother of a North Carolina terror suspect serving 45 years in prison for plotting to attack a Marine base pleaded guilty Thursday to plotting to behead government witnesses who testified against his sibling.

Shkumbin Sherifi, 22, pleaded guilty in U.S. District Court to a single count of conspiracy to commit murder for hire along with a co-defendant, former special education teacher Nevine Aly Elshiekh, 47, of Raleigh.