>> detective gordon detected contacted mary claire flynn. said, will you take a look at these text messages? i said sure i will. and it was utterly shocking. she checked with kelly rayburn, a colleague at the time, and they agreed that those text messages warranted further investigation. >> i couldn't believe what was in. them i had to read them a couple of times. >> clearly it's black and white for you. you know it's wrong. but is it black and white, we are going to go forward with this, is this a crime? i would imagine, for you, it's complicated. >> yes, and with all investigations, it's our duty and responsibility to follow the evidence where it takes us. until the evidence was taking us to carter. >> so the commonwealth office told detectives to keep digging and find out more about michel carter. >> first reaction when you see her picture? >> she's young, just a kid. and the words that she was saying in her text messages, it just didn't seem feasible. >> during the investigation, detective cod more went undercover. at that fund-raiser, h