JOLIET, Ill. (CBS) – Drew Peterson’s lawyers have filed a motion seeking to have his conviction tossed out, because of ineffective counsel by former lead defense attorney Joel Brodsky.

WBBM Newsradio’s Mike Krauser reports, in their motion for a new trial, defense attorneys Steve Greenberg and David Peilet cited – among other things – Brodsky’s decision to call Stacy Peterson’s divorce lawyer, Harry Smith, as a witness.

Smith testified how Drew Peterson’s fourth wife, Stacy, contacted him about getting a divorce from Drew Peterson, and told him she had information about Drew that might be used as leverage in a divorce. He also testified Stacy told him Drew had killed Savio.

LISTEN: WBBM Newsradio’s Mike Krauser Reports

Jurors said Smith’s testimony was crucial to their guilty verdict, but Brodsky defended the decision to call Smith to the stand on Friday. He said Drew himself insisted on putting Smith on the stand.

“He actually threatened that if we didn’t, he was going to take the stand and testify,” Brodsky said. “That would have been the absolute disaster, so to speak.”

According to Brodsky, he could not reveal until now that Peterson wanted Smith to testify, due to attorney-client privilege. But because the defense team is now officially claiming it was a mistake to call Smith to the stand, Brodsky said he can reveal exactly why he did so.

“The reason that Harry Smith was called was because Drew Peterson himself insisted that he be called,” Brodsky said.

He claimed Greenberg was negligent in his cross-examination of Illinois State Police Sgt. Patrick Collins, by failing to introduce the written alibi Stacy provided for Drew for the night of Savio’s death.

Brodsky said Stacy’s written alibi would have countered the testimony of her pastor, Rev. Neil Schori, who said Stacy told him Drew coached her for more than three hours about what to tell police when she was questioned about Savio’s death.

“The actual alibi itself, first of all, it was only less than half a page long,” Brodsky said. “It’s hard to believe – impossible to believe – that an alibi that’s rehearsed for three-and-a-half hours, or three hours, would only be … about a half a page long.”

Brodsky also said the written alibi Stacy provided covered only part of the night of Savio’s death.

“It’s not really an alibi,” he said.

Brodsky argued, if Drew had truly coached Stacy so thoroughly on providing an alibi, he would have made sure she told police he was with her the whole night Savio died.

He said, when Greenberg failed to introduce that alibi as evidence, Drew insisted on calling Smith in an effort to show Stacy’s hearsay testimony was not credible.

However, the jury found Smith’s testimony credible, saying after the verdict that Smith’s and Schori’s testimony were the greatest factors in finding Peterson guilty.

According to sources, Brodsky and Greenberg almost came to blows in a courtroom hallway during the case over whether or not to call Smith to the stand. However, Brodsky insisted the decision was Peterson’s, and the entire defense team agreed at the time.

“Everybody concurred in that decision,” he said.

Brodsky stepped down from the defense team last month, saying the continued infighting on the defense team after the trial had become a distraction to the need to move forward with an appeal.

The judge is expected to rule on the defense’s motion at the next hearing on Jan. 10.