It’s not every day someone forgives a million-dollar mortgage. But that’s apparently the latest twist on the sale of the old Bedford Street police station that’s confounded officials for more than three years. A “satisfaction of mortgage” was signed by Pete Benevides of the Florida company Infinity Mortgage Group. It stipulates “full payment and satisfaction of debt” for its June 4, 2008 sale of the police station to Casper Holdings LLC in Florida, a recording with the city’s Registry of Deeds indicates. The $1.28 million sales price recorded included a $1 million mortgage the Registry listed.