>> detective howard cole said investigators had to take a close look at reid >> any time you have a situation of this nature, nine times out of ten it's inner circle, it's spouse, it's a business associate, a friend. >> remember when reid first went to the sheriff's office on the day quinn was kidnapped? >> did you go anywhere today where you would have to go outside in any fashion >> detectives immediately thought something was suspicious. >> do you know how you got blood or mud on your shoes there >> there's nothing on my shoes. >> it tells us we don't rule anything out. >> and during that interview, investigators learn that quinn and reid had endured some major problems in their relationship. >> what did reid gray tell you about his marriage >> their marriage, for lack of a