Missouri Gov. Mike Parson confirmed David Hosier's execution will be carried out Tuesday, despite several eleventh hour pleas from loved ones and lawmakers to spare the convicted killer's life.

In 2013, Hosier, 69, was found guilty of fatally shooting Angela Gilpin and her husband, Rodney Gilpin, in the hallway of their apartment building in Jefferson City, Missouri, in September 2009, shortly after Angela ended her affair with him.

Hosier was arrested after a police chase in Oklahoma, where authorities seized 400 rounds of ammunition and 15 firearms, including a submachine gun made from a kit that was later linked to the killings. He was sentenced to death, however he has maintained his innocence.

His lawyers have argued his mental health struggles, triggered by the murder of his father, and coupled with his prior military service should save him from death row.

"Saying we are disappointed with Governor Parson's decision to deny clemency to David Hosier minimizes the true depth of our disappointment. David Hosier deserved mercy, and his request for mercy was not a request for freedom, but a request to spend the rest of his natural life in prison," Hosier's attorney, Jeremy Weis, said in a statement to HNGN.

"David Hosier was worthy of mercy based on his service to our country, serving honorably in the United States Navy, and our community, serving as a Jefferson City, Missouri firefighter. This service emulated the life of the man David Hosier admired most, his father Glen Hosier, a Navy veteran and an Indiana State Police Officer murdered in the line of duty while trying to arrest a fugitive when David was just 16 years old. "

"Many people know of David's professed innocence," the statement continued. "His insistence on innocence caused him to reject a plea offer to life in prison without parole. Although the jury heard evidence that no witness placed David at the scene of the Gilpin murders and DNA did not connect him to the crime, after the jury's guilty verdict, no new evidence offered a path to exoneration, and clemency was David's only hope to avoid execution. Our thoughts are now with David's sister's, Kay and Barb, and other family and friends who loved David dearly."

"He displays no remorse for his senseless violence," Parson remarked, adding that this makes Hosier deserving of the death sentence and denied him clemency.

"For these heinous acts, Hosier earned maximum punishment under the law. I cannot imagine the pain experienced by Angela's and Rodney's loved ones but hope that carrying out Hosier's sentence according to the Court's order brings closure."