to kill sherri rasmussen. she seemed obsessed with john and jealous of his new wife. was she the same person with the scary eyes who'd been stalking sherri? to nutall it seemed to add up, especially when he considered this -- sherri's purse and all its contents stolen during the crime were recovered soon after the murder except for one item inside. >> the only thing to this day that was never recovered was john and sherri's marriage certificate. >> after three months of intense secretive investigations, nutall's team needed one last piece of evidence that would either clear detective lazarus or incriminate her. >> we needed a surreptitious sample of stephanie lazarus' dna. our investigators were not cut out for undercover surveillance work. >> so nutall finally brought lapd's internal affairs detectives into the loop, hoping they could close the deal by somehow secretly obtained