(CNN) An Ohio man who authorities accuse of plotting to attack the U.S. Capitol appeared in a Cincinnati court Thursday and entered a plea of not guilty.
Christopher Lee Cornell, 20, has been charged with attempting to kill government employees, solicitation to commit a crime and possession of a firearm.
The first two charges are punishable by up to 20 years in prison, while the third charge can carry a possible sentence of up to five years behind bars.
Authorities say Cornell planned to set off bombs at the U.S. Capitol and then open fire on people as they fled.
He came to the FBI's attention several months ago after posting about his support for violent jihad on social media, according to a criminal complaint.
The FBI launched an undercover operation, with the help of a person who began cooperating in exchange for favorable treatment on his criminal exposure on an unrelated case.
Cornell allegedly told that source he had been in contact with persons overseas, and that he had aligned himself with ISIS.
He did not think he would receive "specific authorization to conduct a terrorist attack in the United States, but stated that he wanted to go forward with violent jihad and opined that this would be their way of supporting ISIL," the complaint said, using another name for ISIS.
According to the complaint, Cornell wrote: "I believe that we should just wage jihad under our own orders and plan attacks and everything. I believe we should meet up and make our own group in alliance with the Islamic State here and plan operations ourselves."