'Not Criminally Responsible' Does Not Mean Walking Free: What the Verdict Actually Triggers in Massachusetts

One claim is circulating every time a Massachusetts murder trial involves a mental-illness defense, and it is wrong: that a verdict of not guilty by reason of lack of criminal responsibility means the defendant “walks free.”

That is not what the verdict does. Not in Massachusetts, and not in most American jurisdictions. Here is what the law actually provides — from the statutes and the courts’ own model instructions, not from social media.

The claim is circulating right now around Commonwealth v. Clancy in Plymouth County, where jury selection entered its second day this morning — five of eighteen jurors seated after day one, with the defense expected to raise lack of criminal responsibility. Nothing in this explainer weighs that case’s evidence or predicts its outcome; it explains the law any Massachusetts jury in such a case is asked to apply.

What the Verdict Means

In Massachusetts, the defense is formally called lack of criminal responsibility. Under the standard the Supreme Judicial Court adopted in Commonwealth v. McHoul, a defendant is not criminally responsible if, at the time of the offense, a mental disease or defect left them without substantial capacity either to appreciate the criminality or wrongfulness of their conduct or to conform their conduct to the requirements of the law.

Two things about that standard are widely misunderstood.

First, a diagnosis is not a defense. Having a mental illness — even a serious one — does not establish lack of criminal responsibility. The illness must have destroyed the substantial capacity described above, at the time of the act. Juries can and do find defendants with genuine psychiatric diagnoses criminally responsible.

Second, once the defense is fairly raised, the burden belongs to the Commonwealth. The prosecution must prove beyond a reasonable doubt that the defendant was criminally responsible. The defendant does not have to prove insanity; the state has to prove sanity. That allocation surprises many trial watchers, but it follows from the same principle as the rest of the criminal law: the government must prove every element of guilt, and a guilty mind is part of what it must prove.

What the Verdict Triggers: Commitment, Not Release

A verdict of not guilty by reason of mental illness does not end the state’s authority over the defendant. It changes the legal track — from punishment to commitment.

Under Massachusetts General Laws chapter 123, section 16, a person found not guilty by reason of mental illness can be hospitalized for observation immediately after the verdict — a period that can run up to forty days — and during that observation or within sixty days of the verdict, the district attorney or the facility’s medical leadership may petition the court for commitment to a Department of Mental Health facility or to Bridgewater State Hospital. The hearing that follows is civil in form, but it is a real proceeding with counsel and findings — and if the court finds the person mentally ill and dangerous, it orders commitment, initially for six months.

That initial commitment is not the end of it. When a commitment period expires, the person may be committed for additional one-year periods — and the court’s own model homicide instructions, given to juries in exactly these cases, state the controlling fact plainly: there is no limit to the number of renewed commitment orders, so long as the person continues to be mentally ill and dangerous.

Massachusetts juries are actually told this when the instruction is delivered — it is given at the defendant’s request or on the judge’s own initiative. Under Commonwealth v. Mutina, a defendant who raises the defense is entitled, on request, to an instruction explaining the consequences of the verdict — precisely so jurors do not decide the case on the false belief that the only alternative to a guilty verdict is the courthouse door.

In practice, commitment after such a verdict in a homicide case can last years or decades. Release happens only when a court is no longer persuaded, at a required hearing, that the legal standard for commitment is still met — a medical and judicial determination, reviewed on a schedule the law sets, not an automatic exit.

Why the “Walk Free” Framing Misleads

The “walk free” claim collapses two very different things: an acquittal on the facts, and a verdict that legally establishes the defendant committed the act but was not criminally responsible for it. The second verdict is not an exoneration. It is a finding that routes a person into a supervised psychiatric-commitment system with indefinite renewal, instead of a prison sentence with a fixed end date.

That distinction matters in both directions. It matters for accuracy — because a jury weighing this defense is not choosing between punishment and nothing. And it matters for the families at the center of these cases, who deserve public conversation grounded in what the law actually provides rather than in outrage at a consequence that does not exist.

None of this tells you how any particular trial should come out. Whether the Commonwealth has proven criminal responsibility beyond a reasonable doubt in a given case is exactly the question the jury exists to answer, on the evidence admitted in that courtroom. But every watcher of these trials should carry the corrected frame: the verdict decides which system holds the defendant — it does not decide whether one does.

Watch for This

When commentary on a mental-illness defense crosses your feed, test it against three questions:

1. Does it state who carries the burden of proof — and get it right?
2. Does it acknowledge that the verdict triggers commitment proceedings, or does it imply release?
3. Does it distinguish the diagnosis from the legal standard?

Commentary that fails all three is not analysis. It is noise wearing analysis’s clothes.

Sources

1. Commonwealth v. McHoul, 352 Mass. 544 (1967) — the Massachusetts standard for lack of criminal responsibility.
2. Massachusetts General Laws, chapter 123, § 16 — hospitalization and commitment of persons found not guilty by reason of mental illness; sixty-day petition window (§ 16(b)); additional one-year commitment periods (§ 16(c)).
3. Supreme Judicial Court, Model Jury Instructions on Homicide (2018 revision, as updated) — the Commonwealth’s burden to prove criminal responsibility beyond a reasonable doubt; the instruction that renewed commitment orders are unlimited while mental illness and dangerousness persist, given at the defendant’s request or on the judge’s own initiative.
4. Commonwealth v. Mutina, 366 Mass. 810 (1975) — a defendant’s entitlement, on request, to an instruction on the consequences of the verdict.

For evidence-first coverage of how these questions play out in real courtrooms, get the free case guide at cassiancreed.com.