(Duluth, MN)  --  A northern Minnesota man has been sentenced to two-and-a-half years in federal prison for stealing another man's identity.  Fifty-seven-year-old Frank Brown of Deer Creek admitted to using someone else's name, Social Security number and birth place when he applied for a passport.  He told investigators he had been using the identity of someone he knew without their knowledge since 1993.  Authorities became suspicious of Brown's application after the victim applied for a passport in May of 2010.  Brown fled police and was arrested last fall in Alabama where he remains in custody.