Retired Air Force Lt. Col. Larry Rendall Brock Jr., who was seen in photos carrying zip ties and wearing tactical gear while storming the Senate chamber last week, was planning to take hostages, prosecutors alleged during a Thursday hearing. Brock was arrested Sunday in Texas and is facing multiple charges. New court filings include a 2018 letter from his former employer saying Brock was fired from the civil aviation company for telling coworkers that he hadn’t killed anyone “for a while,” and talking about killing people of a “particular religion and or race.”

The disturbing new details don’t end there: Brock made a series of Facebook posts ahead of the Jan. 6 attack on the Capitol saying that he was preparing for a “battle” and a “civil war.” “I bought myself body armor and a helmet for the civil war that is coming,” he wrote in one post, according to the court documents. On Jan. 1, he wrote, “I suspect that is what will happen on the 6th. The castle will be stormed. The question is what then?”