Ryan Wesley Routh, the man who tried to assassinate former President Donald Trump, wrote a shocking letter admitting his failure—and offered a chilling reward for someone else to finish what he started. In the letter, which was addressed to the "World," Routh confessed that he couldn’t kill Trump but wanted others to try. He even promised to pay $150,000 to anyone who could "complete the job."

Court papers revealed that Routh left the letter in a box at someone’s house before he was arre...