A Hurricane Katrina evacuee who killed two men in a hail of gunfire in Oklahoma City 20 years ago became the second person executed in the U.S. this week.

Oklahoma executed Kendrick Antonio Simpson by lethal injection on Thursday, Feb. 12, for the double murder of two young men named Glen Palmer and Anthony Jones in 2006. He was pronounced dead at 10:19 a.m. CT.

Simpson, 45, was a New Orleans native who fled to Oklahoma as a Hurricane Katrina refugee in 2005. His execution comes about a month after an emotional clemency hearing during which a parole board deciding his fate heard from the victims' families, a survivor of the shooting, and Simpson himself.

"I'm ashamed of being a murderer," Simpson told the Oklahoma Pardon and Parole Board, saying that he didn't deserve the death penalty. "I'm not the worst of the worst. I'm not a monster."

In a 3-2 vote, the board narrowly allowed Simpson's execution to move forward after hearing from his attorneys about how he had reformed behind bars, obtained his GED, became a "devoted father" to his two sons, and deeply regretted the murders.