The mother of five, whose complete name is Shannon Rogers Guess Richardson, initially informed authorities that the toxic mails were sent by her husband army veteran Nathaniel Richardson, reported Us magazine.
However, after an investigation by FBI, it is found out that it was her, not her husband, who sent the dangerous packages.
The letter sent to the mayor contained strong protests against gun control.
"You will have to kill me and my family before you get my guns. Anyone who wants to come to my house will get shot in the face. The right to bear arms is my constitutional God given right and I will exercise that right till the day I die," the letter read.