Missouri to Execute Man Missing Part of Brain 74-year-old's behavior changed after 1972 sawmill accident By Rob Quinn, Newser Staff Posted Mar 17, 2015 12:54 AM CDT 35 comments Comments This March 6, 2015, photo provided by the Missouri Department of Corrections shows Cecil Clayton, 74, Missouri's oldest death-row inmate. (AP Photo/Missouri Department of Corrections) (Newser) – A 74-year-old man whose behavior changed drastically after a sawmill accident more than 40 years ago will be executed in Missouri today unless the US Supreme Court steps in. Surgeons removed around 8% of Cecil Clayton's brain—including part of the frontal lobe, which controls things like judgment and impulsive behavior—after the 1972 accident, and his lawyers say the brain damage, which left him with an IQ of 71, makes him ineligible for execution, the AP reports. Clayton's lawyers say he became paranoid, delusional, depressed, and prone to violent outbursts after the injury; he shot and killed a sheriff's deputy who was investigating a domestic incident in rural Barry County in 1996, reports NBC. Before the accident, Clayton was a teetotaler and father of five who preached at his own ministry, according to the Guardian, but he split up with his wife and became an alcoholic after the injury. According to the New York Times, he checked himself into a mental hospital for 15 months two years after the accident out of fear he couldn't control his rages. After he emerged, he took a job as a police officer instead of returning to the sawmill, but he quit after nine months because he believed he shouldn't be in a position of responsibility. His lawyers say repeated psychiatric evaluations have shown that he doesn't fully understand why he's being executed and believes God will spare him, but the Missouri Supreme Court voted 4-3 on Saturday not to intervene, the AP reports.