SALEM – A Lynn felon who admitted stealing an undisclosed amount of money from a Sovereign Bank in 2009 is headed to state prison for up to six years.Aubrey E. Dortch, 45, last known address of 44 Merrill Ave., Lynn, changed his plea to guilty Friday afternoon in Salem Superior Court to a charge of unarmed robbery before Judge David A. Lowy.Dortch was sentenced to serve not less than five years and not more than six years in state prison, He has already served 707 days awaiting trial on the case.The charge stems from an incident in Lynn on the morning of April 13, 2009, when a black male wearing a black leather jacket and white Red Sox baseball cap walked into the Sovereign Bank branch, located at 39 Exchange St., and passed a note to the teller just as the bank opened, demanding money.The very frightened female teller turned over the money in a stack also containing a dye pack and the robber fled from the bank into a black minivan.Witnesses told police that the minivan headed down the Lynnway and that the dye pack exploded in the robber?s hands.Following an investigation Dortch was arrested and charged with the crime.Dortch, the father of six children, has convictions in Essex County dating back to 2002.Assistant District Attorney A.J.Camelio prosecuted the case and Mark Schmidt was the defense attorney.