Joseph “David” Caissie's confession to undercover police of murdering Carol King will be admissible in trial, Justice Richard Danyliuk has ruled.

Having examined the confession, obtained in a Mr. Big operation, and compared it to other evidence, Danyliuk found the confession to be reliable enough to be considered in ultimately determining whether the Crown can prove beyond a reasonable doubt that Caissie murdered King.

"The admission of these statements does not mean the Crown's case will, or will not, be sufficient to meet the ultimate onus of proof of murder beyond a reasonable doubt. It simply means the statements ought to be but before the trier of fact at the trial proper because the Crown has demonstrated either that the statement is inherently trustworthy, or that its reliability can be sufficiently tested at trail," he said in his written decision.

Caissie is charged with the 2011 first-degree murder of his one-time girlfriend King. Police set up what is known as a Mr. Big sting, in which undercover officers bring a suspect into a fake crime ring to learn the truth about the crime.

The operation ran from January to July 2016, when Caissie was arrested. During that time he told officers how killed King.

Danyliuk had to analyze the confession in light of the 2014 Supreme Court Hart ruling, which was meant to address concerns that Mr. Big operations would obtain untrue or unreliable confessions, prejudice a judge or jury, or that the confession could be undermined by police misconduct or abuse of power.

Danyliuk dismissed any prejudicial effect the confession might have on the ultimate verdict.

"Frankly, the fact that Mr. Caissie appears willing to engage in smuggling, weapons transport and other unspecified criminality is not of concern to me. He is not charged with any of those crimes."

He agreed with both Crown and defence lawyers that there was no evidence of police abuse of power or process in gaining the confession, such as threatening the target.

"Despite purporting to be a big, powerful criminal organization with cross-Canada influence, violence played next to no role. It seems incredible that a target would buy into such a facade, but Mr. Caissie clearly did."