CHICAGO (CBS) — Drew Peterson’s former lawyers are weighing in on a motion filed by his current lawyers, arguing for a new trial, based, in part, on the decision to call a witness whose testimony was damaging to the defense.

Peterson’s working to overturn his murder conviction, saying his former lead attorney botched the case.

Peterson’s current lawyers say Joel Brodsky threatened to reveal confidential information about Peterson if Peterson tried to fire him.

The filing asks a judge to throw out the murder conviction or order a new trial.

The argument that calling witness Harry Smith, whose testimony was key in the jury’s decision to convict, was malpractice, probably won’t fly, says one of Peterson’s former lawyers.

The reason? Most of the legal team agreed that Smith should be called by the defense.

Earlier this year, Peterson was convicted in the murder of his third wife, Kathleen Savio.

He’s also the only suspect in the disappearance of his fourth wife, Stacy Peterson.

LISTEN: WBBM Newsradio’s Mike Krauser Reports