BANGOR — A former martial arts instructor from Augusta now serving 40 years in federal prison for producing and possessing child pornography had an appeal heard Tuesday by the Maine Supreme Judicial Court about additional state charges involving sexual attacks on two boys.

Wade R. Hoover, 37, through attorney Jamesa Drake, is appealing Justice Michaela Murphy’s rejection of his motion to dismiss the 13 state charges. Hoover, who has pleaded guilty to the federal charges, believes the state charges amount to double jeopardy because federal and state investigators worked together on the case against him.

On Tuesday afternoon at the Penobscot Judicial Center in Bangor, Maeghan Maloney, district attorney in both Kennebec and Somerset counties, said the charges are not duplicative. She told the six justices that the victims’ mothers want Hoover convicted for the gross sexual assaults on their children, and not just the federal child pornography charges.

“I meet regularly with the victims’ moms,” Maloney said. “What they want is gross sexual assault conviction, that what he did be a part of the record for the rest of his life, because it is such a heinous crime.”

Hoover, a 1995 graduate of Hall-Dale High School in Farmingdale, was owner and chief instructor at Koshowarrior’s Martial Arts and the United Martial Arts academies in Lewiston, where he taught children as young as age 3. He was living in Augusta and working as a veterans’ support coordinator at the National Alliance for Mental Illness Maine when he was arrested in October 2012 at his workplace on charges of possessing sexually explicit materials.

Acting on a tip, members of the Maine State Police Computer Crimes Unit and the federal Immigration and Customs Enforcement agency went to Hoover’s office, seized his computer and found dozens of images of child pornography, some of which showed him abusing two boys.

Hoover told investigators earlier that year he had taken a pair of children, who were students at his martial arts studio, for two nights to a cabin in The Forks Plantation in Somerset County. There, he took pictures and a video of himself sexually abusing one boy, an 11-year-old, to whom Hoover also had given sleep medication.

Another video taken from Hoover’s computer showed Hoover and an unidentified man sexually assaulting another young boy, whom officials later said was from Augusta.

At the time of his arrest, Hoover was charged by the state with possession of sexually explicit materials depicting minors under age 12, but that state charge was dropped later in favor of federal charges with higher penalties.

In February 2013 in U.S. District Court in Bangor, Hoover pleaded guilty to the federal charges of filming himself sexually assaulting the boy at the cabin and using his employer’s Internet connection to distribute child pornography images.

Four months later, though, Hoover was indicted by a grand jury in Kennebec County on a dozen new state charges of gross sexual assault on a boy in Augusta between Dec. 11, 2008, and Feb. 13, 2010. When he was arraigned on those charges in June 2013, he initially refused to acknowledge them and had to be removed briefly from a courtroom in Augusta.

The state’s highest court is being asked to consider two issues: whether the state and federal prosecutors charged the same conduct by Hoover and whether Judge Murphy was correct in allowing the state prosecution of the gross sexual assault charges to continue forward. The Maine Supreme Judicial Court issues rulings later in writing, and it was not clear Tuesday when the court would reach a decision.

Hoover, whose earliest release date is Aug. 8, 2047, did not attend the hearing Tuesday.

In the brief filed with the court, Maloney wrote that producing and possessing child pornography “are different crimes from gross sexual assault.” She also argued in support of the judge’s ruling that Hoover could be prosecuted in both jurisdictions, writing that “the Supreme Court has long explained, however, that ‘an act denounced as a crime by both national and state sovereignties is an offense against the peace and dignity of both and may be punished by each.’ ”

She also said, “The state District Attorney’s Office played no role in the federal prosecution, and the U.S. Attorney’s Office is playing no role in the state of Maine’s prosecution.

Maloney argued that cooperation in the investigation was critical because “agencies that worked together to prove that Hoover was drugging young boys, and then videotaping himself … should be commended. They worked together and in so doing prevented the continuation of truly heinous criminal conduct.”

Maine State Police Detective Christopher Tupper and Special Agent William Hoyt of the U.S. Immigration and Customs Enforcement, Homeland Security Investigations, worked together on the case. Tupper and Hoyt previously have described a partnership to help share the workload. Hoyt, for example, filed all the witness interview reports, which Tupper reviewed, but each said their investigation focused on the interest of their particular agency. Tupper has said that the activity that led to the videos and the gross sexual assault are “blended,” because “you can’t have one without the other.”

Drake, Hoover’s attorney, argued that federal prosecutors benefited from having the time to investigate while Hoover was being held in jail on the state charge that was later dismissed.

Drake’s filings with the high court argue that the trial court’s order allowing the state charges should be reversed because Hoover’s alleged sexual assault on children “was the primary reason that (Hoover) received a consecutive 10-year prison sentence for the federal crime of possession of child pornography.” Hoover “has already been punished for that conduct and the state’s prosecution impermissibly threatens to place him in jeopardy twice,” Drake wrote.

On Tuesday, Supreme Court Associate Justice Donald Alexander noted that state and federal authorities cooperate all the time and in particular in drug investigations.

Hoover personally has written a series of letters from jail railing against what he says is double prosecution. In a letter sent from the Somerset County jail to the news media before the federal sentencing in June 2013, Hoover wrote that prosecutors and investigators were spreading misinformation about him and his crimes and that he wanted a fair sentence and an opportunity to be with his family again.

Hoover said false information has been published about his actions, and that he downloaded pornography “to supplement a porn addiction,” and that he “viewed mostly online adult, fetish porn to get my fix.”

In the letter from jail, Hoover said he has never been accused of inappropriate behavior in his 20 years as a martial arts instructor.

Even so, Hoover also wrote that he deserved punishment: “I stepped over the line and committed a bad act.”