A Washington, D.C., Metro Transit police officer, who converted to Islam and once dressed up as Jihadi John for Halloween, was charged Wednesday with attempting to provide material support to ISIS.

36-year-old Nicholas Young of Virginia is the first law enforcement officer to be charged with an ISIS-related crime. According to a criminal complaint unsealed Wednesday, authorities found Young attempted to send money to the terror group ISIS for their recruiting efforts using mobile-based gift cards and an unnamed messaging service.

The $245 was actually sent to an undercover FBI agent and redeemed by the agency. The criminal complaint connects Young to two previously convicted DC-area terrorists, Zachary Chesser and Amine El Khalifi.

Chesser was sentenced in federal court in 2011 to 25 years in prison for aiding Al Qaeda affiliate Al Shabaab. He is also known for threatening the creators of South Park for the show’s depiction of the prophet Mohamed. Khalifi was arrested in 2012 for attempting to detonate an explosive vest in the U.S. Capitol Building and was eventually sentenced to 30 years in prison for his crimes.

Court documents show federal investigators also questioned Young about trips he had taken to Libya in 2011. Young told FBI agents he traveled twice to the North African nation to assist rebels attempting to overthrow the regime of then-dictator Muammar Qaddafi.

“Since I received my first briefing on this matter, [Metro Transit Police] Chief [Ronald] Pavlik and I have worked hand-in-glove with the FBI in the interest of public safety and to ensure that this individual would be brought to justice,” a statement from Metro General Manager/CEO Paul Wiedefeld said.

Young was also searched by Customs and Border Protection on one outbound trip. The search uncovered he had traveled with body armor, a Kevlar helmet, and “several other military-style items,” according to the criminal complaint. He also maintained a large cache of firearms.

In 2015, Young admitted to the Metro Transit Police Department in an interview that he had dressed up as Jihadi John the previous Halloween. According to the criminal complaint, his costume featured a stuffed “orange jumpsuit with paper to portray a headless hostage, and he carried that around with him throughout the party.”

His employment with the Metro Transit Police was terminated Wednesday.