you got to remember, the prosecution's star witness is dave shepard. > shepard is known for telling all kinds of tall tales. >> dave shepard is a con artist of the ultimate magnitude. >> the prosecution painted mike dixon as this puppeteer. >> if he was that manipulative, this was the dumbest planned murder in the history of the united states. to choose dave shepard? >> what he ends up doing in the courtroom just turns this case upside down. >> he made jaws drop in that courtroom. >> this is the kind of moment that you typically see in a movie. >> the case is going to blow up in the prosecutor's face -- and a convicted man walks free tonight. (meg vo) i can see if my endometriosis pain gets better... or i can... (sherry vo) i can just suck it up... or i can... (diane vo) i can tell myself tomorrow will be different... or i can talk to my gynecologist today! (avo) you didn't choose to have endometriosis... but you can choose to ask if orilissa is right for you. orilissa is specifically developed for women with moderate to severe endometriosis pain. in cl

>> his name's dave shepard, s-h-e-p-a-r-d. >> reporter: shepard had a criminal record. >> i didn't have money. i was 17, working part time after school, and he borrowed money from me. >> reporter: he had n had no kn connection to dr. sonnier. but guess who he's best buddies with? dr. dickson. it was an unlikely bromance, a plastic surgeon and a con man. but the two bheirvef cigars and. >> he wanted to be mike. >> reporter: detectives started to believe that mike dickson found the perfect person to help him disrupt rochelle's new life. >> in the minds of investigators, dickson, they think, is a puppet master, and shepard the puppet. >> reporter: six days after the murder, shepard and dickson are arrested. >> two suspects are in custody in connection with the murder of a lubbock physician. >> reporter: after spending three months in jail, shepard confessed, after prosecutors told him they would take the death penalty off the table. >> he's laying on the floor. >> reporter: he told police dickson asked him to follow rochelle and her new girlfriend to get pictures, which led to conversation