In August, the company admitted to lawbreaking that ranged from possessing illegal machine guns at its Camden County training grounds to attempting to land $15 billion in oil and defense contracts in southern Sudan while U.S. companies were barred from doing business there.

The company agreed to pay a fine of up to $7.5 million and entered a deferred prosecution agreement that will essentially expire after three years of good corporate behavior. Only the corporation admitted wrongdoing in that deal.

Thursday’s guilty pleas relate to one of the admissions from the agreement struck in August.

Blackwater used illegal methods of circumventing federal firearm laws when it acquired two Steyr machine guns in 2003 and never registered them as required by federal law. The company acquired 17 AK-47s and 17 M-4s, which it did not properly register with the Bureau of Alcohol, Tobacco, Firearms and Explosives. Instead, the company claimed that it was simply storing the guns for the Camden County Sheriff’s Office.

Blackwater was technically a private firearms dealer, and as such could not possess more than two fully automatic weapons, but law enforcement agencies can.

Tiny Camden County had just 12 full-time deputies at the time, and major violent crimes are a rarity. Blackwater also employed a high-ranking officer at the sheriff’s office as a trainer. After several name changes, the firm is now called Academi.

In recent years, Blackwater has been embroiled in numerous civil and criminal cases. The company agreed in 2010 to pay the State Department $42 million for matters related to the agreement struck in August. The company settled with the families of army officers killed when a Blackwater airplane flying without a flight plan crashed into an Afghan mountain.

Four former employees face weapons and manslaughter charges for a 2007 shooting in a Baghdad square that killed 17 Iraqis. Another guard pleaded guilty to voluntary manslaughter in that case. Two former Blackwater guards were convicted of manslaughter last year for the murder of two Afghans in 2009.

Blackwater was founded by Erik Prince, a former Navy SEAL whose father made his fortune manufacturing auto parts. Prince is a staunch conservative with extensive political connections in Republican and evangelical Christian circles. He built Blackwater into the nation’s biggest private trainer of the military and police at its sprawling compound in Camden and Currituck counties. The company provided security to diplomats in Iraq and Afghanistan, and held a number of classified contracts with intelligence agencies.

Prince’s primary customer was the U.S. government. According to USAspending.gov, Blackwater was paid at least $2.4 billion in federal contracts.

Prince, who has not been charged, has started a private equity investment fund, Frontier Research Group, which aims to provide security, logistical and management services to projects in Africa.

Garst pleaded guilty in November to one count of bulk cash smuggling, but the Army veteran has recanted his earlier admission that the money came from a kickback scheme with an Afghan company. The 51-year-old Kansas man contends the money was winnings from extensive gambling at Bagram Air Base in Afghanistan where he worked as a manager for the company between 2009 and 2011. He claims that his judgment was clouded by post-traumatic stress disorder from earlier deployments in Iraq and Kosovo.

Both the government and defense have declined to comment on the case before sentencing, but each side's sentencing memorandum to the court outlines their arguments.

Assistant U.S. Attorney Jared Maag argued that the defendant used the war in Afghanistan to enrich himself with disregard to the ways the crimes damage the integrity of government contracting, disrespect those serving in Afghanistan and undercut the mission of reconstruction.

Maag contends Garst used his position as a private contractor to steer government subcontracts to an Afghan company that gave him a cut of the proceeds - an illegal agreement that promised to net him at least $610,000, of which he actually obtained more than $200,000.

The government cited his criminal record, including at least eight violations of military law that led to his discharge "under other than honorable conditions." Those violations included fraternization, sexual harassment, falsifying a promotion package with intent to deceive, theft of government property, dereliction of duty and misuse of a government credit card.

The defense's document recounts Garst's troubled upbringing, which led him to leave home at 15 and work two jobs while attending high school. He dropped out of college in 1982 to join the Army and quickly realized he had "found his calling."

A decorated veteran, full-time employee of the Army National Guard and eventually a civilian contractor, Garst served his country most of his life, attorney Christopher Joseph said. While serving in Iraq as a national guardsman, he was in charge of mortuary affairs, verifying remains and processing them to return home.

Joseph wrote that Garst's PTSD symptoms allow him only two or three hours of sleep a night. He has nightmares so vivid he can see the ice poured on the bodies to preserve them, the attorney said. Garst hears voices screaming at him and sees faces of dead soldiers when agitated, Joseph said, and stepping into sunlight reminds Garst of explosives.

The defense argues that Garst suffered from psychological troubles at the time of the crime, saying his capacity for good judgment was impaired. The felony charge drove him to realize the seriousness of his conduct, his attorney wrote.

"If any good has come from Mr. Garst's bad act, it is that the gravity of this situation has awakened him to the need to address his mental health issues - thoroughly and fully," Joseph told the court.