Where does illness end and responsibility begin? The Lindsay Clancy Trial

In a courtroom in Plymouth County, Massachusetts, twelve people have spent four days failing to agree. They told the judge they were deadlocked. He sent them back.

The facts they are considering are not in dispute. Lindsay Clancy strangled her three children in January 2023 and then threw herself from a second-floor window. What the jury cannot agree on is whether she is criminally responsible for it. Her defence says she was suffering from postpartum psychosis. The prosecution says she acted intentionally, rationally and swiftly.

That deadlock is worth pausing over, because it is not a failure of the jury. It is twelve ordinary people running directly into the hardest question the criminal law asks, and finding that it does not resolve cleanly.

The question underneath nearly every criminal offence requires two things: a prohibited act, and a guilty mind. The second requirement carries an assumption so basic that we rarely examine it — that the person choosing to act could have chosen otherwise.

Psychiatric defences exist because sometimes that assumption fails. Where illness has genuinely destroyed a person’s capacity to understand what they are doing or to control it, punishing them achieves nothing that punishment is for. It does not deter, because the conduct was not the product of a deliberating mind. It does not express fair blame, because there was no free choice to blame.

The difficulty is that capacity is not binary. It sits on a spectrum, and the law has to draw a line across that spectrum somewhere. Wherever it draws it, hard cases will sit on both sides of it.

What Scots law actually requires.  There is a persistent public belief that these defences are a soft option — that a diagnosis is produced and responsibility evaporates.  Actually, that is far from the case.

Scotland has two distinct routes, both regulated by the Criminal Justice and Licensing (Scotland) Act 2010, and both much narrower than the public thinks.

The mental disorder defence requires that, because of a mental disorder, the accused was unable to appreciate the nature or wrongfulness of the conduct. Not distressed. Not impaired. Unable to appreciate. And it is expressly excluded where the disorder consists only of a personality disorder characterised by abnormally aggressive or seriously irresponsible conduct.

Diminished responsibility is narrower still in what it achieves. It does not acquit. It reduces murder to culpable homicide, and requires an abnormality of mind that substantially impaired the ability to determine or control conduct. It too excludes psychopathic personality disorder, and it is unavailable where the abnormality was caused by voluntary intoxication.

Neither is new, and neither is imported. Diminished responsibility is a Scottish invention of the nineteenth century, developed by our own courts long before anyone thought to insert it into statute. The 2010 Act tightened and clarified a doctrine that had been part of Scots law for well over a century.

The sceptical case is that psychiatric categories have expanded considerably over recent decades. Conditions that were once marginal are now well populated. Expert witnesses are instructed by the side that expects to benefit from their opinion, and juries are asked to choose between two expert witnesses offering incompatible accounts of the same mind at the same moment. The further the diagnostic map extends, the more conduct falls somewhere on it — and the less work the concept of responsibility is left to do.

There is a further point, less often made. These defences require a jury to make a finding about a mental state that existed at a single moment, months or years earlier, which nobody observed and which cannot be reconstructed. That is not like deciding who threw the first punch. It is a judgment about the unobservable, dressed in clinical language that lends it a precision it does not possess.

Those are real criticisms. The answer to them is not that the doctrine is beyond question, but that the statutory tests are demanding, that the burden rests on the accused, and that juries reject these defences far more often than they accept them — as the deadlock in Massachusetts illustrates rather than contradicts.

What the deadlock actually shows.

The temptation is to read a hung jury as proof that the system is broken. The better reading is that it is working.

Those twelve people are not being asked whether what happened was terrible; everyone agrees it was. They are being asked whether a woman who did it was, at that moment, a person capable of choosing not to. That is a genuinely hard question. A jury that found it easy would be a jury that had stopped thinking.

Whatever verdict eventually comes, it will not settle the underlying issue. The line between illness and responsibility will still need drawing, and it will still be drawn imperfectly, case by case, by juries doing their best with evidence that can never be complete.

Why this matters here.

Cases of this severity are rare. But the question is not.

It arises in Scottish courts regularly, and usually far below the headlines — in the summary case where an accused was clearly unwell, in the culpable homicide plea, in the disposal that sends someone for treatment rather than to prison. Every criminal practitioner in Scotland encounters it, and every one of those cases turns on the same problem the Massachusetts jury is wrestling with.

Where a mental disorder may be relevant to a case, the assessment must be made early, and by someone who understands both the medicine and the statutory test. The defence is difficult to establish and easy to lose through late instruction.

If you or a member of your family is facing a criminal charge where mental health is a factor, call 01389 756785. We will tell you honestly what the position is.  And help where we can.

However, the jury is still out on Lindsay Clancy.