10 years of relentless work pays off for detective in cold case homicide

SIOUX FALLS, S.D. (KSFY) - A 38-year-old cold case has been solved.

The body of a baby boy was found on the outskirts of Sioux Falls back in 1981. Media began referring to the case as "Baby Andrew."

Leads quickly dried up, and it has remained a mystery ever since, until Friday when authorities arrested 57-year-old Theresa Rose Bentaas, who police say is the boy's mother.

Detective Mike Webb has been on this case since 2009 when it was assigned to him to take another look.

Ever since then, he has not stopped trying to solve it. He said he has had many people help him along the way.

Webb said he worked so hard on this case knowing there was a child involved.

"You go through a lot of frustrations. You get knocked down a lot. But you keep getting back up and you don't quit," he said.

Ten years full of frustrations and dead ends.

"These cases are frustrating, disappointing, I think you have to learn you're gonna have more failures than successes," Webb said.

But now he is able to share this big success with his colleagues by his side. That includes Chief Matt Burns, who said he was very proud of his department.

"What you see reflected on my face today is a lot of pride," he said. "It is a big moment for our department and our city, but it's very reflective in where we're at in law enforcement with technology and DNA."

And that technology helped bring some closure to this case for Webb as he heads into retirement.

"It's amazing to have finally some closure on this case," he said. "I think his voice is heard."