The man who planned to kill US presidential candidate Donald Trump left a letter urging someone else to carry out the assassination in case he failed, federal prosecutors have revealed.

“This was an assassination attempt on Donald Trump but I failed you. I tried my best and gave it all the gumption I could muster. It is up to you now to finish the job; and I will offer $150,000 to whomever can complete the job,” said the handwritten note Routh allegedly left in a box at someone’s home.

A photograph of the note was included in the court filing by the US attorney for the Southern District of Florida, made public on Monday. Federal prosecutors included the note as evidence that Routh should remain in jail pending trial.

According to the filing, Routh had left a box at the home of an unnamed individual in the weeks preceding his attempt to kill Trump. The person opened the box following Routh’s arrest and alerted the authorities last week, the Department of Justice said.

“ammunition, a metal pipe, miscellaneous building materials, tools, four phones” and several other letters. 

Other evidence found in the car included a list of venues where Trump was scheduled to appear with dates in August, September and October, as well as a notebook allegedly “filled with criticism of the Russian and Chinese governments and notes about how to join the war on behalf of Ukraine,” according to the New York Post.

“obliterated and unreadable.”