Fargo police said a man sentenced to prison for making threats against President Bush may have had a gun at a rally for the president at North Dakota State University in 2005.
Daniel Cvijanovich was sentenced in January to 19 months in prison for making threats against Bush while he was in prison for a previous conviction.
Police said the Fargo man was at the rally but did not act on his plans to harm the president.
Four Fargo police officers are being recognized by the Secret Service for their work in the case. Detective Paul Holte said Cvijanovich posed a serious threat.
"We did find disguises, we found a weapon that he had stated that he did not have, the notes and the writings in his journals and the information that he was collecting for his own personal use, basically documenting his history and how he was going to set history and and change history forever," Holte said.
A spokesman for the Secret Service office in Minneapolis said authorities are still investigating Cvijanovich's alleged plot at the Fargo rally.
Cvijanovich plead guilty in May 2006 to three counts of damaging government property and one count of threatening to assault a federal officer.
Three times in 2001, Cvijanovich entered the U.S. Federal Building in Fargo and threw a rock through a pane of glass separating the public lobby from the secure portion of the building which houses the local FBI office. Attached to each rock was a note addressed to the FBI.
(The Associated Press contributed to this report.)