CAMPBELLTON, N.B. -- Jean-Claude Savoie has been found not guilty of criminal negligence in the deaths of two boys killed by his escaped python in northern New Brunswick, and now his lawyer says the RCMP broke a deal not to lay a charge in the first place.

"It's been quite a roller coaster road for him to have been implicated in this matter, investigated and at one point told that there would be no charges," Leslie Matchim said.

Matchim said an investigation by New Brunswick RCMP concluded no charge was warranted.

"The investigation does not support an offence of causing death by criminal negligence," reads a report signed by the lead investigator and the head of the major crime unit on Nov. 22, 2013.

That investigation ended three months after Savoie's African rock python slithered through an uncovered ventilation duct to escape from its enclosure and kill four-year-old Noah Barthe and his six-year-old brother Connor, who were attending a sleepover in Savoie's Campbellton apartment.

The file was then subjected to an external review by major crime investigators in Halifax, and they agreed with the initial finding that charges were not warranted.

According to a court document released Thursday, the original investigator sought to have Savoie answer some lingering questions that police had about the morning the dead boys were discovered.

Matchim said they'd agree if they got a guarantee in writing that no charge would be laid.

"And in fact we received that very thing -- a written indication, clearly by the RCMP, that these are the questions and should you provide Mr. Savoie's answers, he will not be charged."

However on Feb. 5, 2014, RCMP Inspector Marc Bertrand was assigned to review the investigation and decided a charge should be laid.

"I hope it bears more scrutiny by someone that the RCMP would give a written guarantee to somebody in exchange for breaking their constitutional right to remain silent that they would not be charged," Matchim said.

Matchim sought a stay of proceedings earlier this year, but was denied.

There had been a publication ban on the nature of that hearing and the decision until it was unsealed by Judge Fred Ferguson Thursday.

According to the decision, Bertrand said the previous officer did not have right to give a guarantee of no charges.

"If what Cpl. Deveau did in giving a written statement to counsel for Mr. Savoie that no criminal charge would be laid amounted to a granting of immunity, it was without the consent of his superiors and beyond his authority as that could only be authorized by the attorney general of New Brunswick," Bertrand wrote in an affidavit.

The trial was allowed to proceed, but without the use of Savoie's answers to the RCMP questions.

The jury returned a verdict of not guilty Wednesday night after deliberating much of the day.

Matchim said the verdict is the ultimate vindication and said Savoie is relieved.