Updated

Attorneys are expected Tuesday to deliver closing arguments in the capital murder trial of an Arizona inmate accused of killing an Oklahoma couple while on the run.

John McCluskey is being tried on federal carjacking, murder and other charges in the August 2010 deaths of Gary and Linda Haas of Tecumseh, Okla. The couple's charred remains were found among the wreckage of their burned-out travel trailer on a remote ranch in eastern New Mexico.

Prosecutors rested their case last week after calling dozens of witnesses, including McCluskey's cousin and girlfriend, Casslyn Welch, and his former prison bunkmate, Tracy Province. Both alleged in testimony that McCluskey was the triggerman.

Defense attorneys, without calling any witnesses of their own, tried to discredit Welch and Province. They accuse the two of cooperating with prosecutors in exchange for leniency. Welch and Province pleaded guilty last year and face life sentences.

The Haases were killed three days after Welch said she helped McCluskey, Province and another inmate escape from a privately run, medium security prison near Kingman, Ariz. One of the inmates was caught a day later in Colorado. The search for Welch, McCluskey and Province sparked a nationwide manhunt.

According to testimony, the trio targeted the Haases for their truck and trailer after having fled through three states in a cramped car without air conditioning. Welch testified the plan was never to kill anyone, just to "get off the grid" and go into hiding.

Prosecutors contend McCluskey had intentions of harming the Haases from the moment he and his alleged accomplices spotted the retired couple at a rest stop.

"He wanted that vehicle, he wanted to stay on the run. And the only way he could do that was to ultimately eliminate the Haases," prosecutor Mike Warbel told the judge Thursday.