the motive, and the opportunity to kill sherry rasmussen. she seemed obsessed with john and jealous of his new wife, was she the same person with the scary eyes who was stalking sherry. to nutall, it seemed to add up. especially when he considered this. sherry's purse and all its contents stolen during the crime, were recovered soon after the murder. except for one item inside. >> the only thing that to this day was never recovered was john and sherry's marriage certificate. >> after three months of intense investigation, nutall's team needed one a last piece of evidence that would clear detective lazarus or incriminate her. >> we needed a sample of stephanie lazarus's dna, our investigators were not cut out for undercover surveillance work. >> so, nutall finally brought l.a.p.d.'s internal affairs