WINDSOR -- A prosecution decision to renege on a plea bargain after prospective witnesses were told the accused would admit his guilt would deprive the man of a fair trial, an Ontario court has ruled.

As a result, Superior Court Justice Renee Pomerance ordered enforcement of the deal Jon-Paul Fuller had agreed to rather than make him stand trial.

"The question is ... whether the state conduct meets the threshold of an abuse of process," Pomerance said in her decision released Friday. "The cumulative effect of the state conduct in this case -- the disclosure to Crown witnesses and the subsequent repudiation -- has deprived the accused of the right to a fair trial."

Police had charged Fuller over a large marijuana grow operation. As is routine, Fuller and the prosecutor -- a senior and highly experienced Crown lawyer -- negotiated a pre-trial deal in which he would change his plea to guilty in exchange for a 90-day intermittent sentence and $25,000 fine.

A senior regional justice in Windsor, Ont., approved the proposed agreement in October last year, with the deal expected to be confirmed in open court days later.

In the interim, proposed prosecution witnesses were told they were no longer needed to testify. Some were given details of the plea deal, one of whom made a Facebook comment that the accused would be going to jail.

At the last minute, however, the Public Prosecution Service of Canada ordered the Crown to rip up the deal, prompting the regional senior justice to send the matter to trial.

Fuller -- a former president of Crime Stoppers in Windsor-Essex County -- sought to stay the proceedings, alleging abuse of process. He argued the prosecution should not have reneged on the deal, and that calling witnesses who knew he had planned to plead guilty would compromise his right to a fair trial.

The prosecution maintained its actions did not affect the integrity of the process. It argued going back on the deal was justified because the proposed sentence was too lenient, court documents show. The Crown also argued the defence could cross-examine witnesses on previous statements if they changed their testimony.

Prosecutors do have the discretion to renege on plea deals, and judges, in general, should not second-guess them, Pomerance said. However, she noted it's different if Crown conduct affects the fairness of the trial or undermines the integrity of the judicial process.

"Witnesses should never have been told about the plea," Pomerance said. "Once witnesses were told about the plea, there should not have been a repudiation."

Little evidence exists as to why the Crown backed off, beyond an email suggesting the proposed sentence was too light. But Pomerance said the prosecutor must have had reasons for negotiating the deal -- approved by a senior justice -- based on the particular facts of the case. No evidence exists that the prosecution service asked about those reasons or knew what they were.

Pomerance also agreed that having witnesses testify after being informed the accused had planned to plead guilty could taint their evidence.

"There could, perhaps, be no greater confirmation of the accused's guilt than his own acknowledgment of it," Pomerance said. "The accused should not be forced to confront witnesses who were improperly told of his intention to plead guilty at a trial that he had reason to believe was not going to occur."

Ultimately, Pomerance ruled, the best remedy was to enforce the plea agreement rather than order a trial or take the drastic step of staying the proceedings. The deal, she said, was a "just and appropriate remedy."

This report by The Canadian Press was first published Jan. 14, 2020.