An ex-con former federal agent will serve up to 15 years in prison for a million-dollar scam that involved a lawyer couple who were killed execution-style inside their Brooklyn home.

Robert Delvicario, once a suspect in the July 2008 double-murder of divorce lawyer Mark Schwartz and his wife, mediator Christina Petrowski-Schwartz, was sentenced yesterday to five to 15 years in prison by Brooklyn Supreme Court Justice John Walsh.

“The defendant stole and laundered over a million dollars in money,” said Brooklyn prosecutor Laura Neubauer. “The bulk of theft was from innocent and unknown victims.”