Army records obtained by NBC 5 Investigates details how the U.S. government spent nearly $5 million to convict Nidal Hasan in the Fort Hood massacre -- crimes for which he wanted to plead guilty.

After several months of filing requests, NBC 5 Investigates received the first detailed accounting of the costs related to the court martial and trial for the former Army psychiatrist convicted of killing 13 and injuring 32 in a mass shooting in 2009. The total bill to U.S. taxpayers was more than $4.7 million.

Hasan, who called no witnesses in his defense and asked only a few questions during the trial, wanted to plead guilty to the charges against him but was forbidden to do so by military law, so a trial had to be held.

On most days in the months leading up to the trial, Army helicopters landed outside of the Bell County Jail to pick up Hasan and ferry him 40 miles to Fort Hood so that he could work on his defense in his private office.

Army records obtained by NBC 5 Investigates show the helicopter rides cost taxpayers more than $194,000. The Army spent more than $200,000 for trailers, apparently including one that housed Hasan's private office, which had been dubbed "Hasan's Hut."

"I mean, it's ridiculous. Why the government bent over backwards for Hasan and not do the same for the people, the soldiers that he tried to kill and killed?" said Shawn Manning, who was shot six times.

Manning and other victims of the mass shooting have not received the same benefits as soldiers wounded in attacks overseas.

Meanwhile, as NBC 5 Investigates first reported, Hasan stayed on the Army payroll until 10 days after he was convicted. Under current Army rules, only civilian employees arrested for a major crime can be suspended without pay, not soldiers.

"It's sickening, you know? To know that there's guys that he had shot, wounded, that are struggling day-to-day and can't pay their bills, and we're flying this guy with his own private helicopter and still giving him a paycheck after he murdered 13 people and tried to murder another 32 people," Manning said.

The new Army records obtained show the biggest pretrial expense was travel.

More than $1 million was spent on travel for witnesses, jurors and lawyers. Another $1 million was spent in expert witness fees, while another $90,000 was spent to house the witnesses.

Other expenses listed in the documents raise more questions than they answer, including:

$222,000 charged on a government purchase card

$94,000 on nontactical vehicles

$51,000 in supplies

$15,000 for cellphones

With the government currently shut down, an Army spokesman at Fort Hood said he was unable to reach people who could answer questions about the pay records provided to NBC 5. In past conversations, the Army has said the helicopter rides were necessary to protect Hasan and his transport team against threats and that many of the other charges were just unfortunate costs of preparing for a difficult legal case.

NBC 5 Investigates will continue to follow up with the Army and ask for more detailed accounting of these records.