ARVILLA (AP) - Kelly Gahlon had been gone about 20 minutes when the bloodhound went after her, charged up with the scent from a gauze pad swabbed across her car seat, tracking her through a shelter in Turtle River State Park, past a set of portable restrooms, then slowly up a hill.

The bloodhound paused on a blacktop path at the top of the hill, first heading one direction for about 30 feet, then making a 180 degree turn, retracing his steps and turning to bolt down the other side of the hill, dragging Grand Forks Sheriff's Sgt. Ron Gibbens behind him, until he found Gahlon behind a row of bushes, dove, knocked her to the ground and punished her face with his wet, sloppy tongue.

"What's it like getting mugged by a dog?" called out one of the 20-some observers, volunteer firefighters and paramedics from small towns outside Grand Forks.

"He needs to work on his people skills," Gahlon called back, wiping the saliva from her face. "He's not a little dog."

Gahlon organizes training sessions for the regional firefighters and emergency workers through a program called Red River Rescue. Gibbens was Monday's guest speaker, along with Joker, the 120-pound bloodhound, and Mattie - actually Matoska, Lakota for White Bear - a yellow lab Gibbens is training as a cadaver dog.

Gahlon, also an Altru paramedic, said the training session ranged from CPR and emergency bandaging to search and rescue work, aimed at preparing the first responders before Grand Forks paramedics or county deputies arrive.

"I respond to all these communities," she said, "but these guys are the first on the scene."

Joker has participated in a few wilderness searches, Gibbens said, and has tracked criminals from the scenes of bank robberies. He is prepared to identify them from a lineup using scent alone.

Like people, Gibbens said, Joker has his good days and his bad. Just now he's preoccupied with a new Dachshund that Gibbens and his wife brought into the family and sometimes has trouble keeping his mind on his work.

"He thinks he's in love," Gibbens said.

Just as often, observers will think Joker is preoccupied when he's really right on track, Gibbens said.

A human scent can waft, like snow drifts blowing from one side of a street to the next, he said. In training sessions, he said, the person being tracked will sometimes be walking down a residential street along a row of houses while Joker tracks him, serious and nose to the ground, from an alley on the other side of the houses.

"Everyone has a specific scent," he said. "You can change your odor (by wearing cologne or perfume) but you can't change your scent."

Unlike some police dogs who are trained to follow footprints as well as scent, Joker works on scent alone. In fact, when his nose is down on the ground, the bloodhound's loose skin will fall over his eyes, leaving only his nose to do the tracking.

Joker usually does his best work with a lag time of 15 minutes or more, Gibbens said, because the human scent is often so strong it confuses him in the first few minutes after someone has passed.

A faint scent is all it takes, he said. Joker has tracked people through the woods up to 30 hours after they were last seen and still hit the mark.

"People just don't believe what he can do," Gibbens said.