OXFORD, Miss. (AP) — A former engineer at a U.S. military air logistics center has been charged with making false statements and obstructing justice during the criminal investigation into a 2017 military plane crash in Mississippi that killed all 16 service members aboard, prosecutors said Wednesday.

James Michael Fisher, 67, was arrested Tuesday after a federal grand jury in northern Mississippi indicted him, according to a news release from U.S. Attorney Clay Joyner.

The release said Fisher is a former lead propulsion engineer at the Warner Robins Air Logistics Complex in Warner Robins, Georgia. Fisher, who now lives in Portugal, made an initial court appearance in Jacksonville, Florida.

A spokesperson for the U.S. attorney’s office in northern Mississippi said she did not have information Wednesday about whether Fisher is represented by an attorney.

Fifteen Marines and one Navy corpsman were killed July 10, 2017, when the Marine Corps KC-130T transport plane broke into pieces in the sky and slammed into a soybean field near Itta Bena, Mississippi.

The plane was based at Stewart Air National Guard Base in Newburgh, New York, and it was taking Marine special operations forces from North Carolina to Arizona for training. The crash was the deadliest Marine Corps air disaster since 2005, when a transport helicopter went down during a sandstorm in Iraq, killing 30 Marines and a sailor.

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The indictment alleges Fisher knowingly concealed engineering documents and made false statements to investigators about his engineering decisions that might have been related to the crash, according to the news release from Joyner.

Fisher faces up to 20 years in prison if he is convicted on the two false statements and two obstruction of justice charges.

Three agencies that are investigating the crash joined the federal prosecutor in announcing Fisher’s arrest. They are the Air Force Office of Special Investigations, the Defense Criminal Investigative Service and the Naval Criminal Investigative Service.