Andrew Brannan

Lawyers for a Georgia death row inmate are asking that he be spared execution, saying his crime was a result of mental illness that can be traced directly to his military service.

Andrew Brannan, who is 66, is to be executed Tuesday for the January 1998 slaying of 22-year-old Laurens County sheriff's deputy Kyle Dinkheller. Authorities say Brannan shot Dinkheller multiple times during a traffic stop.

Brannan's lawyers argue he had no prior history of violence and had been diagnosed years before the shooting with post-traumatic stress disorder resulting from his front-line service in the Vietnam War.

Brannan's lawyers say the jury at his trial did not hear complete details of his service or mental illness.

The State Board of Pardons and Paroles is to hold a clemency hearing Monday.

Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Tags: death row inmate, Andrew Brannan, death row inmate Andrew Brannan, sparing Andrew Brannan's life because of mental illness