SHASTA COUNTY -- Cameron Gamble stepped into the spotlight during the disappearance of Sherri Papini.

Gamble calls himself a captivity survival expert. The slogan on his website is, "Where you go is your business. Getting you home is mine."

He travels the world, negotiating the release of kidnapping victims for desperate families and major corporations. Sherri Papini was not his first case.

In 2015, Gamble negotiated the release of Pastor Cesar Diep, who was kidnapped in Guadalajara, Mexico. He's helped people in other countries, including Honduras, Kenya and Guatemala.

"You may not have the U.S. government coming to your aid," Gamble told FOX40. "What you say and what you do could affect your own outcome."

Since 2010, he has been teaching government employees, humanitarian workers and even missionaries how to survive detainment in foreign countries.

"We don't just teach how to physically deal with captivity. We teach them how to mentally deal with captivity," he said.

Gamble served time in the Air Force, but what makes him most qualified to negotiate someone's release is that he went through the SERE program.

"I went through this program, the SERE program. Survival, evasion, resistance and escape back in 2002 in the Air Force," Gamble said.

SERE is an elite team trained to face any type of survival situation. They learn how to survive behind enemy lines, in the worst moment of their lives.

Every skill Gamble was taught, he now uses at his training facility in Shasta County.

FOX40 was given exclusive access to the site. There are four shipping containers, side by side, each serving a specific purpose in his survival program.

"When my students are in here, I want them to smell, I want them to see, I want them to feel captivity at the most realistic level," Gamble told FOX40.

The first so-called "classroom" was cold and dark. Cement covered every inch of the walls. On one side, there was a two-way interrogation mirror. On the other, there were chains. A single light bulb hung in the middle.

"This would be your typical interrogation cell that you would see in a foreign country," Gamble said.

The next room was more intense than the first. Dirt covered the floor. Jagged pieces of metal and wood were hung haphazardly on the wall.

"This one was replicated after what you might see in the slums of Mexico or the slums of Djibouti," he said. "In this environment, you might not last as long as the last one. Your priority may be to just get out."

The first phase of the course is education, learning the motive of the captors.

"Who is in front of me? What does that person or group want and how far will they go to get it?" he said.

If ransom money is what your captors want, Gamble says your goal should be to stay healthy in captivity.

"If their motive is to kill me, then it sets up my priorities to escape," Gamble said.

In his course, Gamble teaches his clients to work with their environment to get you.

"Can I use something that's on the ground to shim my handcuffs or rip through my duct tape or my rope?" Gamble said.

Phase two is evasion. Once you've escaped captivity, how do you avoid getting captured again?

"We actually train our students to go through the city while they're being chased by the captors they just escaped from, and walk through and transfer back to an urban environment," he told FOX40.

For Sherri Papini's case, Gamble was brought in after she was kidnapped, but his goal and message are always the same -- bring people home safe and alive.

"At the end of the day, I did what I did to help out," Gamble said.

Read Part One of this special report on how Gamble became involved with the Papini case.

Amy Henderson contributed to this report.