Republican candidate for the US Senate in Montana Tim Sheehy has failed to comply with Pentagon regulations regarding the publication of his autobiography "Mudslingers," documents from the Defense Office of Prepublication and Security Review show. Officials found no record of Sheehy submitting the required form for prepublication clearance. His book, covering his time as a Navy SEAL and later career, may add to his growing list of campaign controversies, including discrepancies in his accounts of military service. Montana’s Senate race is crucial, with the Republican challenge threatening Democratic control of the Senate.