Transcript for NY Man to Face 3rd Trial for Wife's 2001 Killing
We'll begin with a New York man going on trial for the third time for the murder of his wife more than 1 years ago. The verdict was guilty in the first two trials but both convictions were thrown out. His children have been standing behind him throughout. ABC's Matt Gutman has that story for us. Reporter: On September 11th, 2001 the wife of millionaire businessman Cal Harris vanished. Michele Harris' van was found at the foot of the family's driveway but there was no trace of the mother of four. This is just an absolute living nightmare. Nobody should have to go through this. Reporter: But with the couple going through a nasty divorce, suspicion quickly fell on Cal Harris. I knew they were focusing on me. I had been completely cooperative with them. Reporter: Police scoured the family's 250-acre property in upstate New York but never found Michele's body or a murder weapon. The investigation dragged on for four more years until 2005 when Cal Harris was arrested for the murder of his wife. It was a shock. We knew there wasn't any evidence so we didn't know how they could possibly get an indictment. Reporter: At his first trial prosecutors argue that tiny amounts of blood found in the Harris home suggested Michele had been attacked there by her husband. A jury found Cal Harris guilty of second degree murder but before he could be sentenced, a new witness came forward with new information. Claiming to have seen Michele arguing with a man who was not her husband on the day she disappeared. Leading the judge to throw out that guilty verdict and in the new trial, Cal Harris was again found guilty. And shockingly, that conviction was overturned, as well, by an appeals court. Today 13 years later Harris' third trial begins. Did you kill Michele? Absolutely not. Absolutely not. And the fact that I'm sitting here and having to go through this is just a horror show. Reporter: But two juries have found you guilty. Two juries that haven't gotten all the information. What the jury will say when they take a look at the entire case is that the police investigation was wanting and that there were other leads that the police should have followed up. Had they followed those leads, the case might actually be solved. Reporter: Standing by him him and Michele's four children who believe their father did not kill their mother. Did you ever ask him what happened that day? No, absolutely not. Why? We didn't have any doubt. He wasn't involved. Reporter: For "Good morning America," Matt Gutman, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.