It’s up to the U.S. Supreme Court whether Missouri will carry out the execution of a man convicted of 13 years ago killing three people, including a Dent County Sheriff’s Deputy.

Earl Forrest (courtesy; Missouri Department of Corrections)

Earl Forrest (courtesy; Missouri Department of Corrections)

Earl Forrest is scheduled to die by lethal injection at the state prison in Bonne Terre between 6 p.m. Wednesday and 5:59 p.m. Thursday. His attorneys, including Lance Sandage, have asked the Court to block the execution based on their argument that the death penalty is unconstitutional.

Forrest does not deny killing Chief Deputy Sharron Joann Barnes, Harriett Smith or Michael Wells in December 2002, but Sandage says the jury that sentenced him to die didn’t hear information about a brain injury he suffered years before.

“PET scans that were conducted showed that. That has really been the thrust of Mr. Forrest’s claim through post-conviction, was trial counsel’s failure to properly litigate that in the penalty phase of his trial,” Sandage told Missourinet.

The appeal to the Supreme Court, however, is solely that the death penalty violates the 8th and 14th Amendments to the Constitution. A request for clemency from Governor Jay Nixon (D) has also been filed. Other appeals for a stay have already been denied.

Prosecutors said Forrest had gone to home of Smith to demand she keep her end of a deal in which he introduced her to a source of methamphetamine. He killed her and Wells at her home and killed Deputy Barnes in a shootout with law enforcement at his own home. He also shot his then-girlfriend and then-Dent County Sheriff Bob Wofford, both of whom survived. He was sentenced to death for each of the three murders.