The tragic case of a Duxbury woman who appears to have killed all three of her children last week has generated worldwide attention. It has also prompted questions about why this happened in the first place, and what the appropriate legal consequences should be. Northeastern law professor and GBH legal analyst Daniel Medwed joined GBH's Morning Edition co-hosts Paris Alston and Jeremy Siegel to discuss the case. This transcript has been lightly edited.

Jeremy Siegel: This is a shocking and difficult case to hear about, to put it mildly. What exactly do we know so far about what happened?

Daniel Medwed: Last Tuesday, around 6 p.m., Patrick Clancy found his wife, Lindsay, outside their home in a state of distress. Apparently, she tried to commit suicide by jumping out a second floor window of their home. Inside the house, according to the police, their three children were exhibiting obvious signs of trauma. It appeared as though they'd been strangled. The kids were ages five, three and seven months. The eldest two kids died shortly thereafter. The third was airlifted to a Boston hospital and died a few days later, on Friday. Plymouth County prosecutors have charged Lindsay Clancy with eight crimes so far: Two counts of murder, three counts of strangulation or suffocation and three counts of assault and battery. A ninth charge is anticipated with respect to the death of the third child. At the moment, evidently, Lindsay Clancy is recovering in a Boston hospital under police supervision and will be formally arraigned on these charges when she's physically able to do so.

Paris Alston: So, Daniel, we are continuing to learn more about Lindsay. Her husband posted a really emotional statement to a GoFundMe page over the weekend, not only talking about his three children and who they were, but also emphasizing that Lindsay was a loving wife, a mother and a nurse, and asking people to forgive her in this case. And the operating assumption here is that her behavior was triggered by some form of postpartum depression or psychosis. What more do we know about that, and how does that inform the case?

Medwed: It's such a fascinating and disturbing case. Paris, as you point out, we're learning more and more about Lindsay Clancy's mental health situation. But first of all, I think it's important to give some general context. Postpartum depression — feelings of extreme despair, hopelessness and anxiety — is extremely common for women in the aftermath of giving birth. An estimated 10 to 20% of women experience postpartum depression. And rarely, but sometimes, it can morph into something called postpartum psychosis, which transcends despair and sometimes is manifested in delusional or disordered thinking, sometimes even what are called auditory hallucinations, voices that can imperil the mother and potentially children in her care. I think it's important to know that while we don't have that much information about Lindsay Clancy, her specific predicament, there are indications that she was really suffering from this. Over the summer, she revealed in an online social media post that she was really struggling with depression after giving birth to her third child. So that detail, plus all of the evidence, as you mentioned, about how she was a loving and doting mother, makes many people speculate that some form of postpartum depression or psychosis played a role here.

Siegel: How, in court proceedings, does a suspect's mental health factor into where things go legally? To what extent do prosecutors take all of that into account?

Medwed: Extenuating circumstances like a suspect's mental health tend to affect the trajectory of a criminal case in several specific ways. First and foremost, in terms of deciding whether to charge the person with a crime at all; and if so, what specific crimes are suitable. Second, it relates to whether or not the defendant could raise what's called an affirmative defense, for instance, insanity, at trial. And finally, it is sometimes a factor in sentencing. If the person is convicted, it can be used to mitigate or reduce their sentence. In Illinois, postpartum depression or psychosis is explicitly allowed at this stage. Here, prosecutors presumably decided that murder charges were warranted. But that decision obviously is somewhat controversial and subject to debate in legal and other circles.

"Because of the complexity of this defense, and because of the uncertain benefits of even prevailing, insanity is rarely deployed in criminal cases."
-GBH News Legal Analyst Daniel Medwed

Alston: So, Daniel, one course of action here could be the defendant pleading the defense of insanity. And assuming that this case eventually goes to trial, do you think Lindsay Clancy would raise that defense? And if so, what all would that entail?

Medwed: It's a very complicated question for defendants in deciding whether to raise that type of defense. So in Massachusetts, you can argue that you lack criminal responsibility and seek what's called a verdict of not guilty by reason of insanity if the following requirements are met: You have to show that because of a mental disease or defect, you were unable to understand the wrongfulness or criminality of your conduct; or even if you could understand it, you couldn't conform your conduct to the requirements of the law. That's a lot of legalese, just to put it bluntly. Does Lindsay Clancy have a mental health issue like postpartum depression that made her unable to understand what she was doing, or even if she understood it, unable to stop it? That's the key question in these types of cases.

Siegel: So let's say this were the defense that Clancy's legal team, that Clancy proceeds, with and she is found not guilty in this situation due to insanity. What would happen to her in that case?

Medwed: Well, contrary to popular opinion, a successful insanity defense isn't the equivalent of an acquittal. It's not a walk-off home run. It just means that instead of going to a prison to serve out a potential prison sentence, she would be handed over to a secure mental health facility for an indefinite period of time. And she'd have episodic mental health reviews to see whether or not the underlying condition had changed and whether she would be safe to be released. But it's quite possible that she would stay in a secure facility for a long period of time. Because of the complexity of this defense, and because of the uncertain benefits of even prevailing, insanity is rarely deployed in criminal cases. I saw some data that suggests it appears in only 0.025% of criminal cases. Of course, it's often in TV dramas and movies, but in the real world, it's very, very rare.

If you or someone you know is having thoughts of suicide, please call the National Suicide Prevention Lifeline at 988 or use the Crisis Text Line by texting “Home” to 741741. More resources are available at SpeakingOfSuicide.com/resources.