Send in the cleaners. After the bodies are gone, Bill Muir makes it look like nothing happened

There's a lot of crime in Chicago. And someone has to clean up the mess afterward. Someone like Bill Muir.There have been more than 400 homicides in the city already this year. After the police have finished at the crime scenes, the cleaners move in. Companies like Bio-One Chicago, owned by Muir's wife, Dawn, specialize in dealing with murders, suicides and what are called "unattended deaths" — people who die alone and unnoticed.

Bill Muir and his wife, Dawn, who owns Bio-One Chicago. (Bio-One Chicago)

As you can imagine, it's not a job for the squeamish. And, often, those who do the dirty work also end up providing emotional support for the survivors.

"When I saw her face and the hugs she gave me...it was right then and there that I knew I was destined to do this." -Bill Muir, Bio-One Chicago crime scene cleaning company

"The first thing I tell them, if it was a loss, is, 'I'm very sorry,'" Muir tells As It Happens guest host Laura Lynch. "I tell them to breathe easy because help is on the way."

He also recommends they not go inside the crime scene. "You want to remember the good part of your loved one, not the unfortunate."

Mourners pay their respect outside of a home on Sunday, Feb. 7, 2016, in Chicago, where six members of the Martinez family was found dead. Bill Muir and his colleagues cleaned up inside the house. (Nam Y. Huh/AP)

Muir is well aware of what victims' families might see. He's cleaned up at a home where a family of six was murdered. At another, a father was bludgeoned to death by his stepson.

He and the others on his crew wear bio-hazard suits at such sites. They use special cleaning products. Then they start with the front door knob and work their way inside.

The company specializes in crime scenes, but also cleans up the houses of hoarders. (Bio-One Chicago)

Muir decided to go into this business after tragedy hit his own family. His brother-in-law killed himself and he helped his sister by cleaning up.

"When I saw her face and the hugs she gave me...it was right then and there that I knew I was destined to do this," he says.

He says he'd be happy if the killing stopped and forced him to find other work. But he doesn't expect that to happen any time soon. In the meantime, the gratitude he feels from his clients keeps him going, even when he's faced with cases where children are murdered.

Bill Muir loads garbage into a dumpster. (Bio-One Chicago)

"I had a 17-year-old boy. Somebody knocked on his back door and, when he opened the door, they shot and killed him," he recalls.

"And his mother was five feet away from me while I was cleaning it. And she was screaming, as expected. But when I was all done, she stood up, smiled and gave me a hug and said, 'Thank you.' There's not too many people who can ever say that's happened to them. So that's the part I love about it, is being able to help."