Still, despite rejecting five appeals stemming from three separate cases, the country's top court made it clear it wasn't condoning the behaviour.
"While the conduct of the police and the Crown was in some respects improper and should not be repeated, there is no basis for concluding that they conspired to obtain a favourable jury," the court ruled in one of the cases.
"What occurred did not constitute a serious interference with the administration of justice, nor was it so offensive to the community's sense of fair play and decency that the proceedings should be set aside as a miscarriage of justice."
In one of the cases, three men — Ibrahim Yumnu, Tung Chi Duong and Vinicio Cardoso — were convicted at trial in Barrie, Ont., of first-degree murder for two gangland killings.
In the others, Troy Davey was also convicted of first-degree murder in Cobourg, Ont., for deliberately killing a police officer, while James Emms was convicted in Barrie of fraud.
Christopher Hicks, the lawyer who represented Davey, said he was "very disappointed" with the ruling.
"I thought this was very much a live issue for the criminal justice system," Hicks said.
"It went to the heart of the system in that it went to the heart of the jury-selection process."
The defence argued on appeal that the Crown had obtained an unfair advantage by having police do extensive background checks on potential jurors.
The Crown used the information — which was not turned over to defence lawyers — to screen out jurors who might have been less favourable to the prosecution, the defence argued.
In the Yumnu case, the Crown did fail to tell the defence about the checks, the high court decided.
However, there was no reasonable possibility the jury would have been differently constituted had the pertinent information obtained from the vetting process been disclosed, the court said.
"The appellants received a fair trial by an impartial jury," the court found.
"There was no appearance of unfairness that would shake the public's confidence in the administration of justice."
The high court adopted similar reasoning in all the appeals.
Despite the finding, Hicks said the Supreme Court had left the door open to further challenges if "something more egregious" were to arise.
The issue of jury background checks has surfaced across the country and several interveners — including the Canadian Civil Liberties Association and Ontario's privacy commissioner — were involved in the appeals.
Normally, background checks can be done on prospective jurors to ensure a criminal conviction has not rendered them ineligible to serve on a jury. However, the checks in dispute went well beyond that.
While the Ontario Court of Appeal had previously upheld the convictions in the five cases, the province's top court did take a different view in a decision last month.
In that case, the Appeal Court ordered a new trial for a man convicted of kidnapping and slitting a woman's throat because it found prosecutors and police acted improperly when it came to jury selection.
In ordering a new hearing for Clare Spiers, the court found a "troubling picture" that unfair vetting had favoured the prosecution.
The regional Crown attorney had asked police to run checks on prospective jurors, saying it would be helpful to have information that would flag for exclusion anyone with a "negative attitude to law enforcement."
Officers not only checked for criminal backgrounds, but also searched driving records and other databases for any police contact with potential jurors.
Two years ago, Ontario's privacy commissioner, Ann Cavoukian, ordered prosecutors to stop collecting personal information on would-be jurors beyond the allowed check for a criminal conviction.
Ontario's Ministry of the Attorney General has previously issued a directive forbidding jury-vetting that goes beyond criminal-record checks.Suggest a correction