The commander of the Massachusetts National Guard, Brigadier General Joseph C. Carter, agreed to resign Monday after military investigators found probable cause that he indecently assaulted a subordinate while on a training exercise in Florida in 1984.
Carter, who has been on administrative leave since March, could not be charged criminally because the statute of limitations has long since expired on the 28-year-old incident.
The Army criminal investigation command did not find probable cause that Carter raped the woman, a 23-year-old Guard secretary at the time of the incident, as she alleged. But investigators concluded he probably touched her inappropriately, engaged in conduct unbecoming an officer, and later made false claims about the incident. If Carter had not agreed to retire, Governor Deval Patrick would have convened a court-martial to remove him.
“It is clear to me that General Carter can no longer serve as adjutant general,” Patrick said in a statement. “This is a disappointing end to a 30-year career of service leadership.”
Carter, who had a long career in law enforcement before he was chosen to lead the Guard in 2007, said neither he nor his lawyer has seen the 5-page Army report, issued Sept. 17. He questioned how investigators could discount the rape allegation and nonetheless find probable cause that he assaulted the woman. “It’s incomprehensible,” said Carter.
In a statement, Carter said he felt vindicated because the rape charge was not substantiated.
“I categorically denied the allegation when it surfaced in 2010 and the Army’s determination supports my innocence,’’ he wrote. “However, I am disappointed that the Army has found probable cause for other alleged offenses. I never assaulted anyone.”
Susan Pelletier, the alleged victim, could not be reached for comment. She lives in Kentucky but was temporarily relocated to Massachusetts to await the outcome of the investigation.
“He raped and beat me and left me,” Pelletier told the Globe in a March interview. She said she was so traumatized by the assault she deserted the National Guard for several months to avoid seeing Carter again.
But Carter’s lawyer, Walter Prince, suggested Pelletier, who, he alleged, has a “long criminal record,” fabricated the charges. Prince said Carter was investigated at least eight times in connection with promotions or security clearances, and Pelletier’s claims were never substantiated.
“No written report of the alleged incident has ever surfaced, not from Pelletier, the military police officers who supposedly found her bruised and bloodied on the beach, a hospital, a medical unit, a local police department, people she allegedly told at the time, or anyone else,” Prince said.
The charges against Carter were originally investigated several months after the 1984 incident after Pelletier reported it to Guard authorities. The investigating officer recommended Pelletier take the matter to police, but she told the Globe she was afraid to press charges.
The allegations resurfaced last year as Carter was under consideration for promotion from one-star to two-star general. The charges put a freeze on the promotion while investigators questioned Pelletier and others involved.
In April, Pelletier reacted angrily when Carter told the Globe he did not remember the night of the alleged attack and denied ever raping anyone.
“What am I supposed to say?’’ she said. “He’s lying. He’s lying about the whole damn thing.”
Governor Patrick, said even though investigators were “unable to reach definitive conclusions about the allegations and federal authorities declined to prosecute .. . . the report raises serious concerns about the general’s actions and his response to the allegations.”
Carter has maintained the allegations were part of a long-running smear campaign by a group of senior Guard officers who opposed his efforts to reform the agency by making them work a five-day week and changing an arcane state law so they could be fired without a court-martial.
His enemies, he said, repeatedly made anonymous complaints to Army officials and tried to derail his promotion.
He said the charges had been pushed by the Guard quartermaster, an officer who clashed with Carter over alleged mishandling of federal funds. Carter ordered the quartermaster, Mark P. Murray, court-martialed after he refused an order from the governor to resign, and Murray aired the old rape charge at the court martial as part of his defense.
Carter, 56, who served in the Guard for 39 years, was the first African-American commander in the Massachusetts National Guard’s 375-year history. He was the youngest member of the command staff in Boston police history and served as chief of the MBTA police for four years. In between, he was the police chief in Oak Bluffs on Martha’s Vineyard.
With more than 30 years of experience in the public sector, Carter will eventually qualify for at least two pensions, one based on his years working for various police agencies and a federal pension based on his military service.
Major General L. Scott Rice, who ran the Guard while Carter was on leave, will continue as interim adjutant general.