Updated

Nearly six months after jury selection began, closing arguments were expected Wednesday in the death penalty trial of an Arizona inmate who kidnapped and murdered a retired Oklahoma couple while on the lam.

John McCluskey, 48, was convicted in early October of murder, carjacking and other charges in the August 2010 deaths of Gary and Linda Haas of Tecumseh, Okla., who were making their annual summer trek to Colorado. Jurors then had to decide if McCluskey was eligible for the death sentence.

Now, the same panel will decide whether McCluskey should be executed or spend the rest of his life in prison with no chance for parole in what is only the second federal death penalty case to be deliberated in the state in a decade.

New Mexico outlawed the death penalty for state crimes in 2009.

Anything less than execution for McCluskey would not be justice, federal prosecutors told jurors at the start of the third and final phase of the trial.

McCluskey's defense team, meanwhile, had argued their client's life should be spared, saying brain damage, a troubled childhood and long-term drug and alcohol abuse made him incapable of controlling his impulses and making reasoned decisions.

McCluskey was serving 15 years for attempted second-degree murder, aggravated assault and discharge of a firearm when he and two other prisoners escaped from a medium-security prison near Kingman, Ariz., in July 2010 with the help of his cousin and fiancee, Casslyn Welch.

One of the inmates was quickly captured after a shootout with authorities in Colorado, while McCluskey, Welch and inmate Tracy Province headed to New Mexico, where they kidnapped the Haases for their truck and travel trailer.

Province and Welch pleaded guilty last year to charges of carjacking resulting in death, conspiracy, the use of a firearm during a violent crime and other charges. They both fingered McCluskey as the triggerman.

The victims, who were high school sweethearts and recent retirees from General Motors, were making their 11th summer trip to Colorado when they were killed three days after the prison break that Welch testified was funded by a drug smuggling ring she and McCluskey ran for prison inmates.