Joshua John Leff, 40, was arrested at his home in Fort Myers and charged with intimidation, sending written threats to kill and possession of a weapon by a convicted felon.
He made the threats on social media sites Bitchute and Gab, the Florida Department of Law Enforcement said in a statement. The department began its investigation after receiving a tip about Leff’s statements and videos inciting violence against minority groups.
Guns and ammunition were found at his home during a police search.
In his posts he praised several mass shooters, including John T. Earnest, the 19-year-old gunman accused of killing one and injuring three inside a synagogue in Poway, California in April. He said he wished they had killed more people.
He is being held in Lee County Jail on $1 million bond.