In a rambling, conspiratorial letter addressed to the FBI, alleged assassin Vance Boelter claimed he needed to kill U.S. Sen. Amy Klobuchar so that Gov. Tim Walz could run for the U.S. Senate, according to two people familiar with the contents of the letter.

In a letter addressed to the FBI, Boelter allegedly claimed the killings were part of a larger scheme orchestrated to boost Gov. Walz’s political career.

The letter is described as 1.5 pages long and “incoherent,” claiming that Boelter was secretly trained by the U.S. military “off the books.” The letter was found in Boelter’s car, according to the Star Tribune,