(REPLAY) In order to believe Sean Ellis is innocent, you'd have to believe, the Boston Police Forensic Unit, took Letia Walker's fingerprints at the courthouse and then proceeded to place a print on the gun that killed Det Mulligan. Did the technology to conduct this conspiracy exist in 1993? Does it even exist now? Letia Walker, Sean Ellis's girlfriend, went on to testify that Sean brought the guns into her house. Mrs. Walker had ample opportunity to recant her testimony, why hasn't she? If you notice, she never denied she touched the gun. Why wouldn't the producers ask Mrs. Waker directly, if she touched the gun? She was sitting right there, on camera. The answer is if she answered truthfully Sean Ellis is guilty. This story proved too good to actually investigate. Trial 4 is so defendant slanted it should come with a warning label.