The drowning murders of three-year-old twins Karen and Krista Hart shocked Newfoundlanders a decade ago, especially when their father, Nelson Hart, was fingered as the killer.
Now prosecutors are asking the Supreme Court of Canada to overturn a lower court ruling that granted Hart a new trial on grounds he should have been allowed to testify without a public audience, and that an elaborate "Mr. Big" operation essentially coerced a confession out of him.
Hart was convicted of first-degree murder in 2007, five years after his young daughters were found dead at Gander Lake, in central Newfoundland.
The tragic case followed a bizarre arc.
According to The Canadian Press, Hart told police initially that he and the girls were at the Little Harbour recreation area when Krista fell in the water.
Hart said he didn't jump in to rescue her because he couldn't swim. Although he had a working cellphone in his car, Hart said he left his daughter at the wharf and drove some 11 kilometres to his home, past a hospital and open businesses, to fetch his wife, who also could not swim.
Police arrived to find Karen dead and Krista floating unconscious in the water. She was later declared brain dead.
Two months after his daughters died, Hart changed his story, CP said. He told police he'd had an epileptic seizure and couldn't remember how the little girls ended up in the lake. Hart claimed he lied at first because he worried he'd lose his driver's licence because of his epilepsy.
With no other witnesses or evidence, RCMP fell back on a Mr. Big operation, an elaborate, controversial sting technique used in other high-profile cases. Undercover officers posing as gangsters recruited Hart, drawing him into a lavish lifestyle and introducing him to other bogus criminals.
The ruse culminated, as it always does, in a meeting with the gang's leader, in this case in a Montreal hotel room where Hart was asked to talk about the deaths of his daughters as a test of his loyalty.
The 90-minute conversation was videotaped and later shown at his trial. In it, Hart starts describing his seizure but the boss cuts him off and tells him not to lie.
He said he planned to kill his daughters because social workers were planning to take them and that he could not accept that his brother might get custody of the girls, CP reports.
Later, Hart was videotaped taking another undercover officer to the scene of the deaths and showing how he shoved the girls off the wharf into the water.
Hart's lawyers appealed his conviction, noting Hart had a Grade 5 education and was on welfare when the sting began. He needed money and was paid more than $15,000 by the fake gangsters, who also intimidated him, the defence argued.
The Newfoundland Supreme Court of Appeal agreed, granting Hart a new trial.
The three-judge panel ruled unanimously Hart should have been allowed to testify in a closed courtroom, finding he had "difficulty in thinking and speaking clearly under stress," CBC News reported.
Two of the three appeal judges also ruled the Mr. Big confession inadmissible, finding Hart was a "a weak, socially dependent personality," which allowed him to be "coerced" into giving the confession. He was essentially "detained" by the state and denied his right to keep silent.
The Crown has sought leave to appeal to Canada's top court, arguing the Appeal Court decision "goes beyond the careful balance struck by...(the) individual's right to silence ... and the legitimate interest of the state in law enforcement," CBC News reported.
It could be months before the court decides whether to hear the case.
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But lawyer Rosellen Sullivan, who helped prepare the Appeal Court submission, said if it does and it upholds the lower-court decision, the Crown's case would be seriously undermined without the Mr. Big evidence.
"I would think there would be no chance for a new trial," Sullivan told CP.
Experts have questioned the use of police Mr. Big operations for years.
An academic review of the technique recommends that Ottawa create guidelines for its use.
"I don't want police to be completely hamstrung in their techniques and tools, but we also want to prevent wrongful conviction," co-author Troy Riddell, a political science professor at the University of Guelph, told Postmedia News. "We shouldn't just leave it up to police to decide where that balance lies."
The study reviewed 153 Mr. Big cases from 1987 to 2011 and found the police method was accepted in all but 13 of them. The technique is not allowed in the United States or Great Britain.