She turns mutts and shelter-rescue dogs into detectives, tracking a scent that may be weeks old.

But these super-sniffers don't hunt down fugitives, bombs or drugs.

They track lost pets to help desperate owners.

This case - a missing Siberian Husky named Libby, last seen more than two weeks ago, in north Dallas.

"I want to go to bed knowing I did everything I could," said owner David Clouston.

Clouston's so eager to find his other Husky, he's hired Karin Tarqwyn, a pet detective, at $90 an hour.

She's an Oklahoma PI who migrated from missing people to missing dogs and now has a team of canine trackers sniffing out other pets usually lost or runaways.

Libby's scent - even weeks old - leads to a nearby alley, across yards, and down a neighborhood street.

"It is an art because you pretty much have to interpret what's going on. I run on the dumb end of the leash," said Tarqwyn.

She's using Cade, a chocolate lab, as the lead tracker.

Libby was spotted just a few days ago at a veterinarian's office miles away.

"One dog tracking another, that's the first I heard of that," said kennel assistant, Gregg McGriff.

Twist, a Jack Russell, picks up the trail.

Tarqwyn says she's worked on over 1,500 cases, 90 percent of which have had some resolution. And she says she can track almost any kind of dog.

Ultimately, no Libby was found yesterday but the hunt continues.

"These dogs that I work with, they point the way," said Tarqwyn.

In the last four and a half years, she's worked in almost every state.

She is a dog detective in high demand.

E-mail jbrady@wfaa.com.