brad jennings. >> he started asking me questions about brad, and he goes, what did jennings say to you his wife having an affair. >> announcer: when "dateline" continues. affair. >> announcer: when "dateline" continues. make fitness routine with pure protein. high protein. low sugar. tastes great! high protein. low sugar. so good! high protein. low sugar. mmmm, birthday cake! pure protein. the best combination for every fitness routine. g ♪ >>> it is a sweet little piece of america, buffalo, missouri. population 3,000 or so, where people tend to know each other's business, and where brad could have a best friend he met when they were both in diapers. so, of course, dale potter rushed over to see brad that very christmas morning. >> he just kept saying, why, dale, why did she do this? he was a mess. >> all of those guns you see in the background there? dale owns buffalo's only gun and pawn shop. so when lisa's death was declared to be suicide and the sheriff returned brad's gun, the one that killed her, brad called dale. >> he said, i don't really want the gun back. >> i can't imagine w