The Dayton (Ohio) Daily News reported that Brian A. Beeson was being held in connection to the appearance of the mysterious envelopes in mailboxes throughout Montgomery County.

While the unaddressed envelopes all contained a powder that was proven not to be a biohazard, the accompanying notes were considered threatening in tone by investigating federal officers.

Since his arrest on Saturday, Beeson, who is being held without bail, has been officially charged with threatening to use a weapon of mass destruction and threatening to transfer a biological hazard.

The paper said a spokesman for the FBI's Cincinnati Division would not comment on any possible motives Beeson allegedly had.