A North Carolina teenager, who was arrested Friday in an alleged terrorist attack on Americans, was charged Monday. The man tried buying a semi-automatic rifle to kill U.S. citizens in a show of support for Islamic State forces, the U.S. Department of Justice said.

According to a spokesperson for the U.S. attorney’s office in Charlotte, Justin Nojan Sullivan, 19, of Morganton is facing weapons violations and a charge of attempting to provide material support to Islamic State.

Court papers indicate Sullivan asked a man, who turned out to be an FBI agent, to make a silencer for him. Sullivan allegedly told the agent he wanted to carry out “minor assassinations” for training purposes before launching bigger attacks, adding he would want to send a video to ISIS authorities.

Sullivan allegedly hoped to kill around 1,000 people. He also allegedly said he would use chemical weapons or car bombs, rob banks and coat bullets with cyanide. However, it is unclear how big a threat Sullivan posed, NBC News reported.

The New York Post reported Sullivan said he had converted to Islam. The FBI tracked the teenager after his father reported Sullivan’s unusual activities to police. The father said in April the family was afraid to leave the house because Sullivan was trying to burn Buddhist objects at home. The activity apparently was inspired by ISIS ideology.

Prosecutors said Sullivan was arrested at his residence after he had received the silencer via mail. He is not the first young American to be arrested on terror-related charges. A number of U.S. citizens, mostly young, have been arrested in recent months, many accused of plotting lone wolf attacks on U.S. soil.

A man in Ohio was arrested for trying to provide material support to ISIS forces. Two other men in Boston pleaded not guilty to plotting to behead police officers.