Plymouth, Massachusetts - The prosecution in the murder trial of Lindsay Clancy has come under fire over a question during the cross-examination of Clancy's former mother-in-law.

On Tuesday, Plymouth County Assistant District Attorney Jennifer Sprague cross-examined Susan Clancy, the mother of Lindsay's ex-husband, Patrick.

"Are you an active member in the Catholic Church?" Sprague asked.

When Susan replied in the affirmative, the prosecutor then asked, "So you're aware that murder is considered a mortal sin?"

Murder Judge makes big call on Luigi Mangione's state murder trial after federal guilty plea

Lindsay's defense attorney, Kevin Reddington, immediately objected before Susan could respond, and the presiding judge called the counsel over for a sidebar.

Jurors were then told not to consider the question, and it was stricken from the record.

In an interview with NewsNation, criminal defense attorney Mark Eiglarsh called the question a "cheap shot" and "irrelevant" to the case.

Similarly, NBC10 chief legal analyst Michael Coyne said Sprague "was way out of bounds," adding, "You can't ask someone about their religious beliefs, you can't ask them how often they go to church, and you can't ask them what church it goes in.

"It has nothing to do with credibility, doesn't support it, and it's absolutely impermissible on cross examination."

Lindsay Clancy is currently on trial over the murders of her three children – five-year-old Cora, three-year-old Dawson, and eight-month-old Callan – in January 2023.

The former labor and delivery nurse has admitted to the killings but pleaded not guilty, with her defense team arguing that she should not be held criminally responsible due to severe postpartum psychosis.

In her testimony, Susan Clancy described Lindsay as a "wonderful mother" who had been "begging for help" in the months before the tragedy, per AP News.