Per the National Football Post's Joel Corry:
"If Aaron Hernandez is implicated in the double murder, contract language gives the Pats grounds to recoup his entire $12.5M signing bonus."
As it currently stands, the Patriots are expected to pay Hernandez a piece his bonus for the 2013 season on 3/31 ($3.25mm per Corry, different values from Miguel), as well as his base salary. Any implication in the double murder "will effectively end Hernandez's grievance for...the signing bonus payment [and] salary guarantees". As of January 8th, additional details linking Hernandez to a double murder (in addition to the murder of Odin Lloyd) are starting to surface.
Per Miguel's absurdly fantastic website, here's a summary of Hernandez's grievances:
Aaron Hernandez has filed two grievances - one for regarding his $82,000 offseason workout bonus money and another regarding his 2013 guaranteed salary of $1,323,000, 2014 guaranteed salary of $1,137,000, and his 2014 guaranteed $500,000 offseason workout bonus money.
The 232,800 offseason workout amount is 40 percent of the offseason workout grievance amount. The 984,800 salary amount is 40 percent of the salary that is being contested in the second grievance.
From the CBA - "When a player salary grievance is filed against a Club, 40% of the amount claimed (or, for a player whose contract qualifies under Article 27, 40% of the player's Salary Cap count, prorated to reflect the number of weeks remaining in the regular season) will be counted in Team Salary until the grievance is resolved or until the end of the League Year, whichever comes first.
If Aaron wins his grievances before the end of this year, another 1,825,200 will hit the Patriots 2013 cap.
Keeping this strictly related to football, Hernandez is expected to be $7.5mm in dead money on 2014 cap. I'm sure there will be additional ramifications for the Patriots if they recoup their lost money from prior seasons, if not in the cap, then at the very least back in the coffers.
$7.5mm in cap speak is roughly the value of:
The sum of the 2013 cap hits of Rob Gronkowski and Aqib Talib
The amount of money to make Aqib Talib the 12th highest paid corner in the league, without touching the currently open cap space
The value of Aqib Talib, is what I'm getting. This would mean that the Patriots could bring back Talib and have some breathing room for other free agency moves, like signging some of the aforementioned players to extensions.