STUPID: The DOJ Releases Ryan Routh Letter

Prior to his failed assassination attempt on President Trump, Ryan Routh wrote a letter that, among other things, offered a monetary reward for anyone that could "finish the job." Why would the DOJ release this document? The current political climate is incredibly hostile right now, particularly towards conservatives and the former president. There are no doubt copycats out there who want to follow in Routh's footsteps. So why would the DOJ release this letter, knowing full-well that it would incite more violence and inspire more hate?