A 20-year-old man from the central U.S. state of Ohio has been indicted for allegedly plotting to attack the U.S. Capitol and kill government officials in a show of support for the Islamic State group.

Christopher Lee Cornell of Green Township, Ohio, was arrested Jan. 14, moments after buying a weapon at a Cincinnati gun store. He was charged with solicitation to commit a crime of violence and attempting to kill a U.S. government officer.

Ohio Man Accused of Plotting to Attack US Capitol is Indicted

Court documents said Cornell intended to set off pipe bombs outside the Capitol and gun down people around the building.

Ohio Man Accused of Plotting to Attack US Capitol is Indicted

Cornell allegedly told an FBI informant that he considered members of Congress enemies and was planning a trip to Washington to check out security at government buildings.

Ohio Man Accused of Plotting to Attack US Capitol is Indicted

Cornell indicated on Twitter that he supported the Islamic State group under the alias Raheel Mahrus Ubaydah, the documents said.

The indictment alleges that the planning took place from August 2014 through January 2015, and that the defendant attempted to persuade another person to join him in his planned act of violence.

According to prosecutors, Cornell was in contact with people overseas about the alleged plot.

Cornell also faces weapons charges. He allegedly possessed two semiautomatic rifles and approximately 600 rounds of ammunition.