A federal judge's hearing on the 1979 murder conviction of Jeffrey MacDonald will go into a fifth day Friday, with testimony from the author of the book on the murders, "Fatal Vision."

Joe McGinniss, who wrote about the 1970 murders of MacDonald's pregnant wife and young daughters, had expected to take the witness stand Thursday, in what some court officials had predicted would be the last day of the hearing on whether the former Army doctor should get a new trial.

But McGinniss' testimony was delayed, as lawyers reviewed crime scene photos and secondhand accounts that Helena Stoeckley, a now-deceased drug user, had privately confessed to being at the crime scene, despite her 1979 trial testimony that she had no memory of the hours during the attacks.

"I hope (the hearing) goes on as long as necessary," said Kathryn MacDonald, who married the convict while he was in prison.

She said witness testimony about Stoeckley's alleged confessions and evidence at the crime scene validate her husband's claim that intruders attacked his family.

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But author McGinniss is sticking by his original narrative of Jeffrey MacDonald as the killer.

"This is the last gasp for him," McGinniss told reporters outside the courthouse. "When he loses here, which he will, this is going to be so thorough, so complete, there's nothing left. The case will finally be closed."

Another prominent author, Errol Morris disagrees. His latest book, "A Wilderness of Error," criticizes the 1970 investigation and 1979 conviction of MacDonald.

Earlier this week, Morris' book got an unexpected review from Sarah Palin, who writes on Breitbart.com, "I sympathize with MacDonald and his defense team because I saw firsthand the twisted way McGinniss operates."

Palin became upset with McGinniss in 2010 when the author moved next door to her Alaska home to write a critical biography about the former vice-presidential candidate.

Today, when reporters asked about Palin's comments, McGinniss said, "They really all belong in the same bed. Jeffrey MacDonald, Sarah Palin and Errol Morris are the best bedfellows I've ever seen. They deserve each other."

Fox News' Mary Quinn O'Connor contributed to this story.

Jonathan Serrie joined Fox News Channel (FNC) in April 1999 and currently serves as a correspondent based in the Atlanta bureau.