had to be sure they had the right person or persons. >> a lot of times, you got one shot at it. and if you don't do it right, that killer could walk for life, and that's the last thing i want to do. >> reporter: coming up, finally detectives believe they've zeroed in on their killer. >> when all these facts come together, there's no other suspec claritin-d relieves 8, including sinus congestion and pressure. claritin-d relieves more. happiness is powerful flea and tick protection from nexgard. nexgard kills both fleas and ticks all month long. and it comes in an easy-to-give tasty chew. so you'll be happy you're keeping your dog protected with nexgard. no wonder it's the number one choice of vets for their dogs and yours.