SIOUX FALLS, S.D. (KELO) — The investigation into the baby Andrew cold case happened by chance in 2008. Detective Mike Webb was in the evidence room when he saw a box tucked away on a top shelf with the word Murder written on it. Inside was a musty-smelling file that had been sitting there for 27 years.

“I immediately saw it was a John Doe, and then it hit me that it was a baby, and right there I’m in. And how can you not? It’s a child. So that’s how it all started,” said Webb.

Tom Hanson: And you took the file home that night?

“I did, doesn’t take long to read it but I kept saying what are we missing here there’s got to be a lot more to this homicide book,” said Webb.

By 2009 DNA testing was more common.

He’s not sure how but Webb says evidence including the blanket Baby Andrew was wrapped in and a pair of underwear found at the scene was destroyed. To keep the case moving forward Webb and his team had to do something they didn’t want to do.

“We knew the only evidence we had was the baby himself,” said Webb.

Webb and his team had to exhume the body to get Baby Andrew’s DNA.

“That was a tough moment, you open that little casket, and we all know how small babies are but to really see how small he was and there was a little rosary wrapped around his hands and there was a little teddy bear that someone had tucked in there. There’s the question of how did you keep going in this investigation for 10 years? That’s it, it’s that simple,” said Webb.

Webb and his team checked the DNA against the criminal data base and came up empty. They kept checking, year after year. Finally, they contacted a company that specialized in genealogy, and found a distant relative in Arizona.

More work led to a connection in South Dakota and finally a perfect match to the Bentaas family in Sioux Falls and an admission from Teresa Bentaas that she gave birth to the baby and left him in a ditch on the outskirts of town when she was 19.

The day after her sentencing there are new gifts left for baby Andrew at St Michael’s Cemetery.

“We visited the grave every year on his birthday. I know the people again the very small circle of people who also put some flowers on there, but no family member did, and I’m not giving away any investigative secrets, but we watched on his birthday we sat in the back and saw, I wanted to see who came to see and guess what? It was cops,” said Webb.

Webb says he and his fellow investigators were Baby Andrew’s voice and to this day they carry a special connection to the baby boy.

“I can’t speak for her complete mindset, I know what she told me, but I say this somewhat loosely, but we were the only people who cared. No one else cared for a baby I mean yeah, so absolutely you feel connected, if I don’t do my job, it’s not going to get done. For this baby, no one else is going to continue to fight and that’s what we did in our section for him yeah, he became ours no doubt,” said Webb.

Webb put in hundreds of hours of his own time to solve this case. He says he had a lot of smart people around him who did the same, in fact, a number of them were in the courtroom yesterday to see the end of the case.