Defence lawyers for Joshua Boyle want an Ontario court to discard portions of the evidence from his estranged wife, Caitlan Coleman, and his in-laws.

The sexual assault trial involving the former Afghan hostages resumed Monday in Ottawa provincial court for one day after a summer recess. With testimony from the Crown's witnesses complete, Judge Peter Doody heard arguments about the admissibility of evidence from Coleman and her family: mother Lynda Coleman and sister JoAnn Rotenberry.

Boyle, Coleman's estranged husband, faces 19 charges, including assault with a weapon, sexual assault and forcible confinement.

The 35-year-old has pleaded not guilty to charges for actions allegedly committed after he and Coleman were freed following nearly six years in captivity. Their three children were born during their time as hostages.

After the couple's release in October 2017, they settled in Ottawa.

Much of the evidence from Coleman, her mother and sister focuses on the alleged controlling and disrespectful tone Boyle directed at his wife.

Her mother and sister's evidence centred on observations about the couple's relationship and the treatment of their children.

The defence argued that most of the evidence from Boyle's in-laws didn't directly relate to the charges he faces.

In July, Coleman's mother said she hardly recognized her daughter when she returned from captivity. She was emotionless, Lynda Coleman told court, and seemed "like a robot or an automaton." Both Lynda Coleman and Rotenberry said Boyle was cold and demeaning toward Caitlan Coleman and expected her to take care of their children and household chores.

Crown lawyer Meaghan Cunningham argued Boyle's alleged demeaning and denigrating ways is relevant to establishing the "narrative" that Boyle physically and sexually abused his wife and held her in captivity while in Ottawa. Cunningham, who in court called this "relationship history evidence," said it was critical for establishing the motive for Boyle's crimes.

"The point of this evidence is it shows a pattern," Cunningham said.

Defence lawyer Eric Granger argued before a break for lunch that much of the evidence Coleman and her family gave referred to the mundane day-to-day happenings of the couple's relationship. These "normal vicissitudes of life," Granger said, didn't touch on the charges that his client faces.

Introducing such evidence "elongates" the trial and may force the defence to defend specific instances that are irrelevant to the charges, Granger said. This would create a "trial within a trial," he added.

The judge will still need to rule on the arguments.

On Monday Doody said he will not permit some of one Crown witness's testimony. Early in the trial social worker Deborah Sinclair testified about the different forms of domestic abuse, and described how an aggressor who was held and mistreated in captivity may be more likely to redirect that trauma toward their victim.

However, while on the stand Sinclair conceded she hasn't done formal, peer-reviewed research on how prolonged captivity affects relationships.

Doody said Sinclair's evidence about domestic violence in captivity is inadmissible, but the rest can stand.

It's not clear whether Boyle will take the stand to defend specific allegations raised by his wife and in-laws. But the trial, which will likely run into the fall, could see the accused have his say in court.