At about 12:15 PDT I learned on Pro Football Talk the Aaron Hernandez case could go federal, meaning the death penalty could be in play. The murders all happened in Massachusetts but the case itself spreads to Connecticut and Florida, making this an interstate crime. That is probably why the federal government is potentially involved and perhaps why Hernandez could be executed.
Given this new info at 12:24 PDT, I now doubt Hernandez is going to walk from this situation now, with the federal case being the reason why.