ESCONDIDO (AP)  An unemployed software consultant had been expected to argue for the dismissal of charges that he amassed large stockpiles of powerful explosives because authorities destroyed the house before it could be combed for more evidence.

Instead, George Jakubec on Monday admitted in a deal with prosecutors that he made the deadly weapons at his ranch-style home and robbed three banks since 2009.

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Jakubec, 54, pleaded guilty to brandishing firearms while robbing or attempting to rob banks. He faces a minimum sentence of 30 years in prison when he is sentenced June 13, but prosecutors could recommend less time if he cooperates with investigators. Jakubec faces a maximum penalty of life in prison.

In the plea agreement, Jakubec acknowledged making and storing explosives and weapons at his home in the San Diego suburb of Escondido, including nine detonators, 13 grenade hulls and large quantities of the highly unstable Hexamethylene triperoxide diamine, or HMDT, which can explode by someone stepping on it.

He also admitted to having significant amounts of Pentaerythritol tetranitrate, or PETN, the explosive used in the 2001 airliner shoe-bombing attempt.

In the deal, he agreed to reimburse San Diego County the $541,000 it cost authorities to destroy the home on Dec. 9, in a carefully orchestrated burn that played out on television screens across the U.S.

He also agreed to pay the medical bills of a gardener who was injured when he stepped on explosive powder, to compensate neighbors for any damages to their homes, and to reimburse Bank of America nearly $55,000.

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Jakubec pleaded guilty to brandishing a firearm while he robbed a San Diego bank branch of $42,012 on Nov. 13, 2009, and returning with a firearm to the same branch two weeks later in an attempted robbery that was foiled when he spotted a security guard.

Jakubec acknowledged in his plea agreement that he robbed other Bank of America branches in San Diego of $1,480 on June 25, 2010, and $10,400 on July 17, 2010.

As part of the agreement, prosecutors offered to drop charges of making and storing explosives and robbing the banks.

Jakubec, who rented the house for more than a year, was arrested after his gardener, Mario Garcia, stepped on chemical residue in the backyard on Nov. 18, 2010, and suffered eye, chest and arm injuries. Authorities said they found crates of grenades, mason jars of white explosive powder and jugs of volatile chemicals.

U.S. District Judge Larry Burns had scheduled Monday’s hearing to consider a request by Jakubec’s attorney, Michael Berg, to dismiss all charges because authorities destroyed the home before it could be searched for evidence that may have helped his case. Burns rejected that argument in December when the attorney sought to delay the home’s demolition.

“This situation potentially posed a significant threat to public safety, and we are glad this chapter is closed,” San Diego County Sheriff Bill Gore said.

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