something, some kind of evidence to back up what you've seen on tape? >> the look in his eye on that tape was -- >> that's all you needed? >> that's what i needed. >> or is it that you cannot stand living in this kind of doubt any longer? you had to make a decision, and that was the decision you made? >> absolutely not. i saw the truth on his face in that tape. >> the man who ran the undercover sting, lead investigator robert burret, insisted his team took all precautions to make sure denis did not lie when he met with mr. big. >> we're always mindful of false confessions -- >> allegations are made all the time, i suppose. >> correct. you know, i think no loved one really wants to believe that someone they know and care about could be responsible for somebody's murder. >> in fact, the mr. big undercover technique has been repeatedly upheld by canada's supreme court. and although the rcmp did not find any physical evidence to corroborate denis' confession to mr. big and his gang, it turned out they did have evidence that was perhaps much more compelling, and they got it