FARGO (AP) - Police say they found a gun and disguises at the home of a man sentenced to prison for making threats against President Bush, and they believe he may have had the gun at a 2005 rally for the president in Fargo.

Authorities said the items turned up in a search of Daniel Cvijanovich's home more than a year after the 2005 rally at North Dakota State University, while they were investigating threats he made against the president to another inmate.

Cvijanovich was sentenced in January to 19 months in prison for telling a fellow inmate that he wanted to kill President Bush.

Police said Cvijanovich was at the 2005 rally but did not act on his plans to harm the president.

Charles Sullivan, a Fargo police investigator, said he believes Cvijanovich had a gun at the rally. He said Cvijanovich told authorities that he did not go through with his plans to harm the president because he thought he was being watched by an undercover Secret Service agent.

"As he was moving forward, somebody, he later stated, looked at him funny, and he thought that that person was possibly an undercover Secret Service agent, so he decided not to go through with his plans," Sullivan said.

Detective Paul Holte said authorities found notes and journals in which Cvijanovich described "how he was going to set history, and change history forever."

Cvijanovich has not been charged in connection with the rally. But U.S Attorney Drew Wrigley and Special Agent John Kirkwood of the Secret Service in Minneapolis say authorities are still investigating and the case remains open.

"When you have a person convicted of this type of charge - he remains a person of interest," Wrigley said Wednesday.

At his sentencing in January, Cvijanovich said he was innocent and was the victim of lies, threats and heavy-handed tactics by the government.

Authorities said Cvijanovich made threats against the president while he was serving time for damaging government property and threatening a federal officer in 2001. He was convicted of those charges in May 2006.

In sentencing Cvijanovich, U.S. District Judge Ralph Erickson said Cvijanovich has a history of mental illness, violent fantasies and "some kind of a strange need for fame."

Erickson also sentenced Cvijanovich to three years of supervised release, including one year in a halfway house and two years on electronic monitoring. Cvijanovich was ordered to stay away from any political gathering of federal office holders or candidates, and avoid contact with three inmates who testified against him.