A man convicted of killing a sheriff's deputy and two other people in 2002 is scheduled to be put to death in what could be Missouri's last execution for some time.

Earl Forrest was convicted of killing Harriett Smith and Michael Wells in a drug dispute and Dent County Sheriff's Deputy Joann Barnes in a subsequent shootout at Forrest's home. The 66-year-old is scheduled to be put to death Wednesday evening.

Missouri has executed 18 men since November 2013, including six last year. Forrest would be the first in 2016.

The pace of executions is expected to slow because most of the remaining death row inmates have pending appeals or have been declared unfit for execution. Missouri's death row population has been dwindling as juries sentence fewer people to death.