Patrick Clancy took the witness stand Monday as the prosecution's opening witness in the murder trial of his ex-wife Lindsay Clancy, who is accused of strangling their three young children inside their Massachusetts home. His testimony offered the jury firsthand accounts regarding the circumstances surrounding the deaths.

The trial appears to hinge on questions about Clancy's mental state at the time of the alleged crimes, with legal experts weighing whether she suffered a severe psychotic episode or acted with calculated intent. References to the psychiatric medication Seroquel and descriptions of her experiencing a 'big spiral' suggest the defense strategy emphasizes mental health factors, while prosecutors argue the killings were deliberate and methodical.