BOISE, Idaho — Cadaver dogs are highly trained canines that can help law enforcement agencies track down human remains and other clues to help close a case.

After a private investigator claimed that his cadaver dogs were alerted to human remains near where DeOrr Kunz Jr. was seen, KTVB set out to see how they're trained to sniff out human remains.

Paula Cudd owns and operates Precision K-9 Training in Boise but she's also a cadaver dog handler for the last 20 years. Cudd has assisted law enforcement agencies on numerous investigations throughout her career.

When it comes to how these dogs can distinguish human and animal remains from each other, she says it all comes down to how that got was trained.

"I've been working with, search and rescue dogs for 15-20 years and working with Cadaver dogs for about 15," she said. 

Cudd's Ziva, a 10-year-old German Shepard, is certified by the North American Police Dog Association as a cadaver dog.

MORE: Investigator: Cadaver dogs alert on human remains at campground where DeOrr Kunz Jr. disappeared

Ziva's training is similar to dug dogs, and she has learned how to track human remains down over her ten-year career.

"She's at that veteran stage where it's kind of smooth sailing now," Cudd said.

Part of the training process for cadaver dogs is being able to tell the difference in smell between human and animal remains. These dogs then have to only alert their handler of human remains.

"That would be considered a distraction. So, we train with dead animals or food and the dog must ignore all but the target odor," she said.

Cudd and Ziva went through a mock search for KTVB to show off Ziva's ability. Cudd hid an old hip bone she uses for training purposes on her property and had Ziva search for it. 

Cadaver dogs are trained to alert their handler when they get a 'hit,' a smell of their target. When they find it, their work is rewarded with a treat. Ziva indicates when she has a hit by either sitting or laying down in front of the spot. During her mock training, Ziva got three 'hits' in three different areas.

However, getting a cadaver dog to find the right scent requires human remains to establish the correct smell.

"One of the easiest training aids to get is placenta because its blood and tissue, a lot of times we'll start with that," Cudd said.

Cudd said when she works a case for law enforcement, they will typically call her and ask if she is available on certain dates to search a location. She isn't always compensated for her time and work spent on a case. She told KTVB it isn't about the money for her, it's about helping law enforcement.

"You train and if you can help someone find closure or help an investigation, it's exciting," she said.