Wichita Falls Fire Department responded to a hazardous material incident shortly after 11 a.m., where inmate Roger Hardy, 52, is charged with assault on emergency service personnel, assault on a peace officer, terroristic threats against a public servant and 911 abusive calls. 

The fire investigator said that a letter from the county jail was sent to Spectrum location in the 3000 block of Maurine Street. 

Officials said the letter stated the substance in the envelope was ricin; however, it was discovered it was not ricin and the substance was determined to be harmless. 

The inmate who allegedly sent the letter has not been questioned as of noon on Thursday. 

We will update this as more information becomes available.