Gunner Fisher, an 18-year-old from Big Rock, Tenn. who investigators believe to be the owner, claimed to have purchased multiple weapons, including an AR-15, extended magazines for the AR-15, a rifle scope, and a Saiga-12 shotgun. They also say Fisher posted photos with these weapons and firearms as well as a machete and tactical vest.

Few people noted last December's arrest of Gunner Joseph Fisher for threatening to commit mass violence. But Antioch High School shooter Solomon Henderson took notice, including it in his diary.

Federal agents arrested a teenager over a plot to carry out a mass shooting at a Nashville mosque, News Channel 5 reported on Monday. The plot had first been flagged in December by Court Watch, according to reporter Phil Williams,