Lindsay Clancy's lawyer asks judge to investigate juror and check his phone

The defence lawyer for a Massachusetts mother accused of murdering her three children has asked a judge to investigate a juror in the case.

The proceedings against Lindsay Clancy ended in a mistrial and acrimony this month after the jury failed to reach a unanimous verdict.

Her attorney, Kevin Reddington, wants the court to probe mobile phone use by "Juror Doe" during deliberations as well as a questionnaire he filled out.

A lawyer for Michael Desronvil, the lone juror who wanted to find Clancy guilty, said the latest defence motion was a "Looney Tunes" attack on his client for doing his civic duty. Desronvil has said there was "enough proof that she [Clancy] knew exactly what she was doing".

The juror forewoman has claimed in a media interview that Desronvil had expressed reasonable doubt about Clancy's guilt, which would require him to find her not guilty. He denies this.

Clancy has not denied killing her three children, Cora, five, Dawson, three, and Callan, eight months, at the family's Massachusetts home.

Her attorneys argued she was not guilty by reason of insanity, that she was struggling with postpartum psychosis at the time.

Prosecutors said Clancy made a calculated decision to send her husband out of the house on an errand so she could strangle her children.