Federal agents say a truck driver warned that he would commit a mass shooting at a church in Memphis, Tennessee, on Thursday.
Court records filed Monday say Thomas Matthew McVicker was apprehended in Indianapolis before the plan could be carried out.
An FBI special agent says in an affidavit that McVicker made "credible threats to conduct a mass shooting and suicide."
McVicker's friend in southern Alabama this month told a Florida FBI agent that McVicker was considering "shooting a church up" or killing people on the street.
The affidavit doesn't specify a motive, nor does it identify a specific Memphis church.
Court records list McVicker's address as Punta Gorda, Florida. The records don't list a lawyer who could be reached for comment on McVicker's behalf.