(Bloomberg) -- A former senior FBI official was sentenced to four years and two months in prison for conspiring to violate US sanctions and launder money while working for Russian billionaire Oleg Deripaska.

Charles McGonigal, 55, was a special agent in charge of the Federal Bureau of Investigation’s Counterintelligence Division in New York, where he oversaw efforts to root out foreign spies and led investigations of Russian oligarchs, including Deripaska. After retiring in 2018, he went to work for the billionaire, digging up dirt on a Deripaska rival, MMC Norilsk Nickel PJSC President Vladimir Potanin, McGonigal admitted in pleading guilty in August.

The sentencing on Thursday by US District Judge Jennifer Rearden in Manhattan caps the downfall of a high-flying federal agent whose record included work on the Sept. 11, 2001, terrorist attacks. McGonigal also investigated the 1996 explosion of TWA Flight 800, which killed 230 people, and the 1998 bombings of US embassies in Tanzania and Kenya. He retired after 22 years with the FBI.

McGonigal’s 2016 appointment to the vaunted counterintelligence post should have been the “crowning achievement” of his career, but he “was not content to serve only the country that trusted him with one of its most important counterespionage jobs,” prosecutor Hagan Scotten told the judge before sentencing.

Measure of Clemency

“He started using his title and his power to develop contacts he could later go into business with,” Scotten said. “He was looking to turn his credentials into cash from the people who would pay him for the special knowledge the FBI had given him.”

Seeking clemency, McGonigal, his voice breaking, told the judge that the case had been “mentally and physically exhausting” for him and his family and friends. He said he had a “deep sense of remorse” and took full responsibility for his actions.

The judge said his offense was “extraordinarily serious” and required “a serious term of incarceration,” noting that his actions undercut sanctions imposed by three US presidential administrations and that he occupied one of the highest intelligence positions in the country. His acts posed “great risks to national security,” she said.

But she said other factors, including his “long and distinguished” career, his admission of guilt and a demonstration of remorse support a sentence “modestly” below federal sentencing guidelines, which called for a punishment of up to five years.

Prosecutors had asked Rearden to give McGonigal the maximum punishment. His legal team was seeking a sentence without any prison time.

Tense Times

McGonigal’s punishment comes amid acute tensions between Russia and the US over the Kremlin’s war on Ukraine. US sanctions on Russia and some of its wealthy elite, many with links to President Vladimir Putin, include those over the 2022 invasion as well as earlier measures. Washington imposed sanctions on Deripaska and other wealthy Russians tied to Putin in April 2018.

McGonigal was arrested in January at John F. Kennedy International Airport on his return from a trip to Asia. He still faces sentencing in a separate case, in Washington, after admitting he lied to the FBI to hide foreign travel and received a $225,000 loan.

As special agent in charge, McGonigal oversaw an investigation into Deripaska. Deripaska is the single biggest shareholder in Russian power and metals giant En+ Group International and has a net worth of $3.2 billion, according to the Bloomberg Billionaires Index.

In pleading guilty, McGonigal admitted he was paid $17,500 for doing “open-source” research on Potanin, Russia’s richest person, according to the Billionaires Index. He agreed to forfeit the $17,500. Prosecutors had said they could prove that McGonigal and a co-conspirator planned to share files that were found on the dark web relating to Potanin for a fee of $625,000 to $3 million.

In the Washington case, McGonigal is charged with taking $225,000 in cash from a New Jersey businessman while still working as head of counterintelligence in New York. The New Jersey man had worked for Albanian intelligence decades ago.

McGonigal traveled outside the US with the man, who allegedly introduced him to the prime minister of Albania and to a Kosovar politician. McGonigal failed to file the required reports detailing his foreign travel, prosecutors said.

The case is US v. McGonigal, 23-cr-00016, US District Court, Southern District of New York (Manhattan). 

(Updates with courtroom statements in first and second sections.)

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