The long-awaited trial of the two men accused of murdering Laura Babcock is expected to answer many questions, beginning with the most basic — what happened to her?

The jury trial that begins today in Toronto will be overseen by Ontario Superior Court Justice Michael Code and is expected to last 10 weeks.

During that time, the Crown will at last reveal its evidence about the disappearance of Babcock while attempting to prove her former boyfriend and his pal were behind it.

Missing person

Babcock was reported missing in June 2012. Her body was never found.

She was 23 at the time, a recent University of Toronto graduate.

But the months leading up to Babcock's disappearance were rocky. She had been working in the online sex trade, police confirmed, and had recently moved out of her parents' Etobicoke home.

Still, for friends and family, the troubles Babcock was dealing with didn't explain her disappearance. There was always hope she would appear.

Then, in the spring of 2014, Toronto police declared Babcock dead and charged her former boyfriend Dellen Millard and his friend Mark Smich with first-degree murder.

It was painful news for Babcock's family and friends. And the alleged circumstances of her death, about to be made public for the first time, won't be any easier to accept.

The theory and the body

Police believe Millard and Smich killed Babcock on July 3 or 4, 2012. Each is charged with one count of first-degree murder.

At the trial, the Crown will argue that Millard, 32, and Smich, 30, burned Babcock's body in a large commercial incinerator on a Cambridge-area farm once owned by Millard.

Dellen Millard, left, and Mark Smich, right, are accused of first-degree murder in the death of Laura Babcock. (Facebook, Instagram)

The allegation means the trial will proceed without what is often the key piece of evidence in a murder trial: the victim's body.

Although rare, murder trials — and convictions — can happen without bodies. But it presents challenges for the Crown, as well as openings for the defence to exploit.

'We don't even know if she's dead'

Tad Dibiase is a former federal prosecutor in Washington, D.C., and the author of No-Body Homicide Cases: A Practical Guide to Investigating, Prosecuting, and Winning Cases When the Victim Is Missing.

Former U.S. federal prosecutor Tad Dibiase has studied hundreds of murder cases where the body has not been found. (Nobodycases.com)

Dibiase said that prosecuting cases without a body isn't an easy job, and it's one that begins with trying to prove something that's firmly established in other murder cases.

"The most common defence in a no-body case is the most logical one: 'We don't even know if she's dead,'" Dibiase said in an interview.

If the death can be established, prosecutors then struggle to prove exactly how, where and when the victim died.

"You're starting in a poor position without that basic information," Dibiase said.

Convictions possible

Still, prosecutors have secured convictions in murder cases where there is no body, and there are examples in Canadian courts.

In 2001, Timothy Culham was convicted of murdering Toronto antique dealer Hugh Sinclair, whose body wasn't discovered until a year after the trial.

Lawyer David Butt prosecuted the case for the Crown, and said it involved weaving a "circumstantial web" around the accused.

"A no-body case is the difference between demonstrating reality and eliminating speculative possibilities until you're down to only one inevitable conclusion," Butt said in an interview.

More recent examples include the case of Lyle and Marie McCann, the Alberta couple who went missing while on a road trip in 2010.

Their bodies were never found, but Travis Vader was convicted of manslaughter and sentenced to life in prison for their deaths.

Lyle and Marie McCann were last seen alive July 3, 2010. Their bodies have never been recovered, but Travis Vader was convicted of manslaughter for their deaths.

In June, William Sandeson was convicted of first-degree murder, which carries an automatic life sentence, in the death of fellow Dalhousie University student Taylor Samson, whose body has not been found.

Strong evidence needed

After researching 492 no-body trials in the United States, Dibiase found they had an 86 per cent conviction rate.

Some things are easier for the prosecution in such cases, according to Dibiase's research. He said most of the cases involve men allegedly killing women and more than 50 per cent are domestic in nature.

"So your suspect is a little more obvious," he said.

Dibiase said the high conviction rate is also due to the fact that, without a body, prosecutors only take strong cases to trial, given they're missing a crucial piece of evidence.

In the one such case Dibiase prosecuted, that was the situation.

"I didn't have a body, but I had a wealth of other evidence," he said.