Lindsay Clancy's Lawyer Asks Judge to Investigate Holdout Juror

Lindsay Clancy's lawyer, Kevin Reddington, is asking the court to allow for a thorough investigation of the holdout juror ... including access to his phone records and a review of his 2021 criminal charge for allegedly assaulting his wife.

The attorney filed a document in court recently asking the judge to let his team see the confidential juror questionnaire and "Juror Doe's record from the statewide domestic violence registry."

Reddington is asking for the juror's mobile phone records -- calls, texts, and data from August 27 through September 4.

The time period covers the dates the jury was deliberating over whether Lindsay should be found guilty of murdering her three kids.

The request also asks the court to preserve all the jury notes and the court's responses.

As you know ... the holdout juror -- Juror #10 at trial -- has publicly identified himself as 48-year-old Michael Péguy Desronvil. He says he was convinced by the prosecution of Lindsay's guilt ... despite all other 11 jurors believing there was enough reasonable doubt for a not guilty by reason of insanity plea.

Reddington has blasted Desronvil -- though not by name -- in the aftermath of the mistrial ... claiming he ignored the judge's instructions.