A Washington Metropolitan Area Transit Authority officer was arrested Wednesday for providing material support to ISIS, CNN reported Wednesday.

Nicholas Young was arrested by the FBI “following more than a year of investigation,” according to the CNN. This is the first case of a U.S. police officer being arrested and charged with aiding ISIS.

Officials have said there is “no evidence of any threat to the D.C. Metro system,” according to CNN.

Young, 36, of Fairfax Va., was arrested Wednesday morning at the Metropolitan Police Headquarters in D.C. “and his employment was terminated,” according to The Washington Post.

“Young, at the request of an undercover federal agent, sent codes for mobile messaging cards that Young believed would be used by Islamic State fighters overseas to communicate, according to an indictment filed in federal court in Alexandria, Va.,” The Post reported.

Metro Transit Police Chief Ron Pavlik said in a statement reported by The Post that “the investigation into Young began years ago when his office went to the FBI with concerns.” Young has been monitored by the FBI since 2010.

Young is set to appear in court later Wednesday.