GONE: Volunteers put up photos of Amber Dubois before a candlelight vigil in March.

What happens to a family when the worst happens?

On tonight’s “48 Hours” episode, “Taken: The Amber Dubois Story,” we follow an abducted child’s family from the first few horrific days when the media, the neighbors and the whole country focused on finding Amber to the terrible moment they learn that their child’s dismembered remains were found and her killer arrested.

But the episode doesn’t end there. Incredibly, CBS’s correspondent, Troy Roberts, actually sits down with the inhuman monster John Gardner — who had not just killed 14-year-old Amber, but also another young girl, Chelsea King — for an interview in his jail cell.

When a child goes missing, the first person the cops focus on, of course, is the last person to see the child alive. In this case, that person was Dave Cave, who lived with Amber’s mother, Carrie, and was the father of her second child. Dave called and considered Amber his daughter.

Just before Amber left for school, she and Dave had a bit of a tiff, but he says they patched it up, and sent her on her way, as he did every day, for school.

Then, Dave started acting out of character. For one thing, he did not go to work — which was unheard of — and then he unexpectedly showed up at Carrie’s office with roses, something he had never done before. He said it was just an impulse. The cops thought it was to cover his tracks.

Eventually, Amber’s tortured mother began to believe it, too — that the man she loved and lived with had possibly murdered her child. Carrie moved out with their little daughter, totally destroying what was left of the family unit. It wasn’t until the real killer was found that she came to believe he was innocent.

In the last segment of the show, the monster, Gardner, himself, sits down for an interview with CBS and tells Roberts, “I’m probably going to twiddle my thumbs in some solitary confinement and beat myself up for however long I’m around and eventually it will happen. Eventually someone will come and get to me. That will be a release for me. It’s either going to be that or I end up killing myself, one of the two. I can’t stand to be confined. I’m like an animal. Just like they said. I’m an animal.”

No, Gardner. Animals that kill are put down. Humans that kill too often get to live long and grow fat on our dime.