Nancy Mace Says Mental Illness Does Not Excuse Murder as Lindsay Clancy Trial Ends in Mistrial

A viral graphic attributed to Rep. Nancy Mace says:

“Every serial killer in history has been mentally ill in some way, shape, or form. Doesn’t mean Ted Bundy or Jeffrey Dahmer were not guilty because of it. Same goes for Lindsay Clancy.”

The quote is genuine. Mace recently made essentially those exact remarks while commenting on the highly publicized Lindsay Clancy murder case.

But the first sentence is a sweeping claim that should not be treated as an established scientific fact.

Mace really made the statement

The quotation circulating in the graphic matches a recent post from Mace's account. She specifically compared the Clancy case with Ted Bundy and Jeffrey Dahmer, arguing that mental illness does not automatically eliminate criminal responsibility.

Her comments came amid intense public debate surrounding Clancy's trial and the role that postpartum psychosis and other mental-health conditions played in her defense.

Mace has repeatedly emphasized that mental illness is not, by itself, a justification for murder. In another recent statement, she wrote that mental illness is not a justification for murder.

The Clancy case ended without a verdict

The timing of Mace's comments is important.

On September 4, a Massachusetts judge declared a mistrial after the 12-person jury could not reach a unanimous verdict following seven days of deliberations. Reports indicated the jury was split 11-1.

That means Clancy was not acquitted and was not convicted.

The charges remain pending, and prosecutors can decide whether to seek a retrial. A mistrial caused by a hung jury generally does not prevent the prosecution from trying the case again.

What was the defense arguing?

Clancy did not primarily dispute that she caused the deaths of her three children.

Instead, her defense argued that she lacked criminal responsibility because of severe postpartum mental illness, particularly postpartum psychosis.

The prosecution presented expert testimony challenging that explanation. One prosecution psychiatrist testified that aspects of Clancy's account of hearing a voice directing her to kill her children were inconsistent with his clinical experience and raised questions about whether she was psychotic at the time.

So the central legal issue was not simply:

“Was Clancy mentally ill?”

It was closer to:

Did her mental condition make her legally incapable of being held criminally responsible for what she did?

Those are very different questions.

Mental illness and legal insanity aren't the same thing

This distinction is crucial to understanding Mace's argument.

A person can have a diagnosed psychiatric disorder and still be legally responsible for a crime.

Conversely, some legal systems recognize circumstances in which a severe mental disorder can prevent criminal responsibility.

In Massachusetts, the relevant legal question concerns whether a mental disease or defect left the defendant without substantial capacity to appreciate the wrongfulness of the conduct or to conform her conduct to the law.

Therefore, saying that someone was mentally ill doesn't automatically establish an insanity defense.

That was precisely the dispute at the heart of the Clancy trial.

But is Mace right that every serial killer has been mentally ill?

This is the weakest part of the graphic.

There is evidence that mental-health problems and psychiatric disorders are common among serial murderers, but “every serial killer in history” is far too categorical.

A Cambridge University Press review of research involving 55 male and 55 female serial killers reported documented mental-health issues in nearly 90% of the male serial killers studied and 43% of the female serial killers.

That is a striking finding — but it still doesn't equal 100%.

Research also distinguishes between conditions such as psychosis, mood disorders, personality disorders and psychopathy, which is not synonymous with mental illness in the ordinary sense.

A meta-analysis of research on psychopathy and homicide found a meaningful association between psychopathic personality functioning and lethal violence, but psychopathy itself should not simply be equated with psychotic mental illness.

The FBI's research on serial murder likewise treats serial murder as a complex behavioral phenomenon rather than something explained by a single psychiatric diagnosis.

So Mace's broader point — that mental illness does not automatically excuse murder — is different from her universal statement about every serial killer.

The Bundy and Dahmer comparison

Mace invoked two of America's most notorious serial killers to make her point.

Her argument is essentially:

Even if a murderer has serious psychological problems, that fact alone doesn't mean the person is legally innocent.

That general legal principle is sound.

But individual criminal cases cannot be reduced to whether someone was “mentally ill.” Courts consider the particular diagnosis, the person's mental state at the relevant time, the applicable legal standard and the evidence presented at trial.

That is why Clancy's case required weeks of expert testimony rather than simply determining whether she had a psychiatric diagnosis.

The mistrial changes what can be said about Clancy

Because the jury did not reach a verdict, it would be inaccurate to write that Clancy was found legally responsible — or legally not responsible — for her children's deaths.

Neither happened.

The case ended in a mistrial.

Prosecutors have not yet made a final decision about whether to retry her, and a further hearing is scheduled for September 29.

That means Mace's statement that the same principle “goes for Lindsay Clancy” is an argument about how her case should be viewed, not a description of a final court determination.

What the graphic gets right — and wrong

Accurate:

• Mace made the quoted statement.
• She explicitly compared Clancy with Bundy and Dahmer.
• She argues that mental illness does not automatically eliminate criminal responsibility.
• Clancy's defense centered on severe postpartum mental illness.
• The Clancy trial ended in a mistrial after a deadlocked jury.

Needs qualification:

• “Every serial killer in history” is an absolute claim that available research does not establish.
• Mental illness and legal insanity are not interchangeable.
• Clancy has not been acquitted or convicted; there was no verdict.
• Whether her mental condition legally excuses her conduct remains unresolved.

Bottom line

The quote attributed to Nancy Mace is authentic, but the graphic mixes a legitimate legal argument with an overly broad factual claim.

There is substantial evidence of mental-health problems among serial murderers, but it is not accurate to state as an established fact that every serial killer in history has been mentally ill. And in the Lindsay Clancy case, the courts have not yet determined whether her mental condition made her legally responsible for the deaths of her children.

The immediate legal reality is simple: the jury deadlocked, the judge declared a mistrial, and the case remains unresolved.