From the New York Times:
The N.F.L. player Aaron Hernandez, who was charged with murder Wednesday, is also being investigated in connection with a double homicide in Boston in 2012, according to two law enforcement officials who spoke on condition of anonymity because the investigation is continuing.
Hernandez helped lead the Patriots to the Super Bowl two seasons ago.
It was not clear when investigators began to look at Hernandez in connection with the double killing or what they believe his involvement may be.
Hernandez, 23, was charged with murder and five gun-related offenses in Attleboro District Court in Massachusetts on Wednesday in connection with the murder of Odin Lloyd, 27, whose body was found in a North Attleborough, Mass., industrial park June 17. Hernandez pleaded not guilty and was held without bail. On the murder charge, he faces a life sentence without parole.
One official said investigators were exploring a possible connection between the two cases that could explain a possible motive for the Lloyd killing.
The person said investigators were examining the possibility that Lloyd was killed because he had information about Hernandez’s suspected involvement in the 2012 double homicide, but cautioned that that was somewhat speculative at this point.
So, this is all speculation at this point, but I want to bring up the possibility that this execution-style murder of Lloyd might have been a cold-blooded, rational response to a previous murder as an example of a phenomenon that's almost totally overlooked in the death penalty debate.
Think about it from a game theory standpoint. Say, you murdered two people in 2012 and have so far gotten away with it. In Massachusetts, the maximum penalty is life in prison: there's no death penalty. So, why not murder a witness who could rat you out?
Well, there are practical reasons, like you might get caught for the latest murder (which may be what happened here). Presumably, though, you think the odds of getting away with another murder are better than the odds if the witness lives. So, the incentive structure in Massachusetts looks like this:
Thus, in terms of punishment incentives, the only thing Massachusetts has to deter you from murdering witnesses is lower punishments for the original double homicide. Instead of life in prison, maybe they'll let you out in 20 years. Maybe they'll toss in some Willie Horton-style furloughs. (After all we all now know that anybody who objected to Willie Horton's furlough is a white racist, and what could be worse than that?)
But maybe the public doesn't think being extra nice to double-murderers to keep them from becoming witness-murderers as well is a good deal.
That's where the death penalty could come into play, changing the incentive structure:
Now, perhaps these cases are rare. I don't know. What seems odd to me is that despite all the debate over the death penalty, the subject of its usefulness to punish and potentially deter witness murdering almost never comes up.
There are a number of other life in prison situations where the lack of a death penalty is a problem. I often cite the obscure Sandra Bullock movie Murder by Numbers, in which she plays a detective interrogating an updated Leopold and Loeb pair of thrill killers (Ryan Gosling and Michael Pitt). It was a classic Prisoners' Dilemma game theory situation in which the two killers have a good chance of walking if they keep their mouths shut. (Confessions are useful not just in and of themselves, but that they help the cops recover a lot of physical evidence, as well.)
But why should one defect on the other if the punishments for both are life in prison? The threat of the death penalty gives an incentive to one to rat out the other: He pulled the trigger! I was just along for the ride. Give him the death penalty!
Keep in mind, however, that this situation increases the chances of the non-trigger puller getting the death penalty because the trigger-puller defects first.