Updated

A Gulf War veteran facing possible federal execution should be allowed to get a brain scan before President Bush decides whether the soldier should be put to death, a Senate Republican said Wednesday.

Decorated Army veteran Louis Jones Jr. is scheduled to die by lethal injection March 18 at the federal prison in Terre Haute, Ind. He has exhausted appeals but has asked President Bush to spare his life. He blames childhood abuse and exposure to nerve gas during the Gulf War for his killing of Pvt. Tracie McBride.

"He should not be executed until he has the MRI to determine if there is brain damage," Texas Sen. Kay Bailey Hutchison said. MRI is an abbreviation for magnetic resonance imaging, a high powered brain scan.

Hutchison has championed research by Dr. Robert Haley, an epidemiologist with the University of Texas Southwestern Medical Center, on Gulf War veterans. She has secured $11 million in federal money to support his studies, including $1 million this year.

Haley's research has shown that some Gulf War Veterans' illnesses can be attributed to brain damage caused by toxic substances, particularly sarin nerve gas. His studies also have shown that the sickest soldiers have lower levels of an enzyme whose purpose is to protect the body from such toxic and lethal substances.

Jones, 52, has admitted to killing McBride after kidnapping her from Goodfellow Air Force Base in San Angelo, Texas, and raping her.

Defense experts testified during his 1995 trial that he suffered from brain damage from abuse as a child and post-traumatic stress from his combat tours in Grenada and the Gulf. Prosecutors brought in their own experts to dispute the claims.

Haley said in Jones' clemency petition that Jones suffers from brain damage, not a psychological illness. He based his diagnosis on a review of medical records and discussions with psychiatrists.

Jones' petition is before Bush now.

Hutchison said she would like to see a further study of Jones, including whether he had had violent outbursts.

She said if the brain X-ray shows he has brain damage and he has not had previous problems with violence, the judicial process should begin again in his case.

McBride's family opposes a halt to Jones' execution.