Plymouth DA’s case against William Senne violates principle of double jeopardy

It’s understandable why many state troopers want to see William Senne spend more time in prison. In 2003, while he was driving with a blood-alcohol level above the legal limit for an 18-year-old like him, Senne struck trooper Ellen Engelhardt by the side of Route 25 in Wareham. She was left in a permanent vegetative state for years, until she eventually died in 2011. Senne, who was a teenager at the time of the crash, pleaded guilty to charges stemming from the incident in 2005, but served only 2 ½ years, a sentence decried at the time by law enforcement.

Now, the Plymouth County district attorney, Timothy Cruz, is seeking to put Senne back behind bars by using a loophole in the constitutional ban on trying a defendant twice for the same crime. Senne’s 2005 plea was for reckless endangerment and causing bodily injury while driving drunk. Now Cruz is bringing a new charge on the same underlying actions — this time for vehicular homicide, on the reasoning that Engelhardt’s death in 2011 was caused by the 2003 crash. If convicted, Senne could face 15 more years in prison.

It’s difficult not to sympathize with the prosecutor for using every tool at his disposal. But this action is unwarranted. Even though he has the legal leeway to do so, Cruz is violating the spirit of the double-jeopardy ban by pursuing Senne again. He should drop the case.


Normally, the process is clear: Once criminal defendants are convicted or acquitted, they cannot be tried again for the same crime. So, for instance, Senne can never be punished again for reckless endangerment in the 2003 incident. But courts have ruled that fresh charges can be brought if they are sufficiently different from the earlier charges. A hypothetical defendant who was acquitted of robbing a bank still could be convicted later of shooting the guard, since the two actions are clearly different.

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In this case, the death of Engelhardt eight years after the crash is the new element. Yet it defies common sense to hold that another prosecution of Senne, who is now 28, is anything other than a second shot at punishing him for the same crash. It is especially unfair because of the possibility that his 2005 guilty plea will be used against him. That alone ought to be the tip-off that this prosecution runs afoul of the double-jeopardy principle.

The ban on double-jeopardy prosecutions, so often a plot device in crime dramas, has endured for a reason. It provides finality to criminal proceedings. It also gives convicts confidence that if they make good after leaving prison — as Senne, now a successful Cambridge realtor, apparently has — they won’t spend the rest of their lives facing the possibility of going back to jail. If Senne’s punishment in 2005 was too light, that’s a problem to be solved by putting harsher sentences on the books. Seeking to send him back to prison now, though, would be a misuse of the prosecutor’s power.