A man convicted of killing two Alberta seniors says he converted to Islam in custody and has suffered a variety of abuses at the hands of guards and inmates – both because of the high-profile case and his newly adopted faith.

Travis Vader testified about his religious conversion on Tuesday during a sentencing hearing on two counts of manslaughter in the deaths of Lyle and Marie McCann.

Mr. Vader told court on Tuesday that he converted in 2012, and that he remains a practising Muslim. It is the first public mention of Islam by Mr. Vader, who has spoken often to media in the years since his arrest.

The two St. Albert seniors, who were 78 and 77, disappeared en route to meet family in British Columbia in the summer of 2010. Their burned motorhome and an SUV they had been towing were found later in rural areas west of Edmonton.

Mr. Vader was convicted of two counts of second-degree murder in their deaths after a trial last spring. At trial, a variety of circumstantial, witness and DNA evidence linked Mr. Vader to both the McCanns and their property.

Their bodies have never been located, but the blood of both seniors was found in their SUV, as was a hat belonging to Mr. McCann, which had a bullet hole in it.

Because of a legal error in his original judgment, Justice Denny Thomas later substituted two manslaughter convictions against Mr. Vader in the seniors' deaths. Given the time Mr. Vader has already spent in custody, his sentence could range from time served to life in prison.

Mr. Vader has been vocal about his alleged mistreatment while in custody, and has filed a million-dollar lawsuit charging mistreatment by correctional and justice officials and the RCMP. The defence is seeking to have the conditions of Mr. Vader's time in custody taken into account in his sentence on the manslaughter charges.

A week-long sentencing hearing began Monday with a series of emotional victim-impact statements from members of the McCann family.

On Tuesday, Mr. Vader testified to an array of alleged maltreatment by police and correctional officers, beginning with what he described as an "absolutely humiliating" and "traumatizing" strip search after his arrest on unrelated charges on July 19, 2010, just more than two weeks after the McCanns were last seen.

"I still remember to this day … standing there buck naked in front of the world, basically," Mr. Vader said.

After his arrest, Mr. Vader alleges he was held in segregation at the Edmonton Remand Centre with "the worst of the worst" offenders and in "absolutely gross" conditions.

He said he was subject to three incidents where human feces were inserted into his cell, and was repeatedly heckled by guards who asked him whether he killed the McCanns and where their bodies were.

"The staff was not concerned about my well-being," he told court. He described being put into a remand disciplinary unit as "like being thrown to the wolves."

In his time on remand, Mr. Vader says he was also held in overcrowded conditions, given terrible food, unable to get cream to treat a facial rash caused by a communal shaver and falsely accused by guards of using drugs.

Questioned by Crown prosecutor Ashley Finlayson why he had sworn his oath on the Bible in court on Tuesday morning, Mr. Vader said Islam recognizes all divine scriptures. Asked about a time when he was seen drinking during the fasting period of Ramadan in July of 2016, Mr. Vader said maybe he "forgot or made a mistake," but added, "there's more to Ramadan than just fasting."

He described practices around eating and drinking in daylight during Ramadan as "guidelines."

He said he would get his meals during the day during Ramadan but saved them for later, and was "under a microscope" about whether he was eating during Ramadan. He accused the correctional centre staff of "denying him religion."

Mr. Vader appeared in court with his right hand bandaged, after what he told court was "an unrelated event." The cause of the injury was not disclosed.

Mr. Vader has been granted bail on a number of occasions in the 6 1/2 years since his initial arrest, but was in and out of custody after being rearrested on a variety of drug, property, assault and breach charges.

Asked outside court whether he had any sympathy for Mr. Vader in light of the testimony, the McCanns' son, Bret, didn't hesitate.

"Zero," he said. "I heard, 'Woe is me, I'm a victim here,'" Bret McCann said. "Instead of who the real victims are: my parents."