March 21, 2013  -- A longtime activist who caught criminal animal cruelty on videotape at an Idaho dairy farm said he's not going to be deterred by the aggressive push by some state lawmakers to restrict the use of undercover cameras.

"We'll find a way. There's going to be a way we keep doing this," the veteran investigator told ABC News.

The activist, who has requested ABC News refer to him as "Pete," worked as an employee at Bettencourt Dairies in Idaho for three weeks last year on behalf of the animal rights group Mercy for Animals. As detailed in an ABC News report last week, Pete recorded employees beating, kicking and dragging dairy cows around the farm – animal abuse violations that resulted in criminal charges against three workers.

But investigations like the one at Bettencourt Dairies may not be possible in other states across the country should farm management and agriculture lobbyists get their way. Nine different state legislatures are considering so-called "ag-gag" bills that would place restrictions on the filming or use of undercover video on farms. Five states have already passed similar laws.

The new state laws are part of a campaign being waged by lobbyists for the agriculture industry to put an end to the undercover videos that have cast a harsh light on the operations of some large-scale farms, often called factory farms by their critics, which has in turn prompted public outrage.

"I hate to think that these investigations will dwindle," Pete said. "These 'ag gag' laws are just protecting criminals."

READ: 'Ag Gag,' More States Move to Ban Hidden Cameras From Farms

Fearing arrest under laws pushed by the agriculture industry, animal rights activists have already halted undercover camera investigations into animal cruelty in the five farm states, including Iowa and Utah, where the laws went into effect last year.

"If you think that chilling speech and closing the curtain on our food production is winning, then yes, they've won," Wayne Pacelle, CEO and president of the Humane Society of the United States, told ABC News in the original report.

Going Undercover in 'Factory Farms'

To conduct his investigations, activist Pete said he goes undercover for weeks at a time, usually in a city or town he's unfamiliar with. He uses his legal name – which he says he has had to change twice – on job applications, but does not disclose his affiliation with animal rights groups. Under the law passed in Iowa, that's now a crime for which someone could serve a year in jail.

But even before the new laws, farm management used to try to ferret out activists themselves. Farm officials often perform background checks to see a potential employee's address history, Pete said, and if something doesn't check out with what's been put on an application, red flags are raised.

"It's happened where I've been exposed before I even started a job. Animal agriculture groups have fought hard to expose my identity and keep me from working," Pete said.

Investigations Pete has conducted over 11 years have resulted in at least 15 criminal cases brought by law enforcement, he said.

The American Farm Bureau insists that these criminal animal cruelty cases are rare.

"There can be bad actors in every segment of society and we don't defend them. But the vast majority of farmers and ranchers have animal care, animal stewardship, as their top priority," Kelli Ludlum, Director of Congressional Relations for the American Farm Bureau told ABC News in October.

In the Bettencourt case, Pete said the first day on the job he saw another employee dragging a cow on its side inside a milking barn, in full view of a manager who was present. The incident was recorded with a hidden camera and was one of several acts of animal cruelty that he documented during his employment. He said when he felt he had enough proof of animal cruelty, Mercy for Animals turned the footage over to local law enforcement. Criminal charges were brought against three employees; one of those pleaded guilty to misdemeanor animal cruelty.

Owners Luis and Sharon Bettencourt told ABC News that as soon as they found out about the abuse, they fired the employees responsible. They question why Pete, working as their employee, didn't tell them directly what he had witnessed.

"We would have taken care of it," Luis Bettencourt said.

Several of the new proposed bills have included a mandatory rule to inform law enforcement immediately after abuse is witnessed, which Pete said would make building a solid case difficult.

In light of the new laws and proposed legislation, Pete said he won't do anything illegal, but will work closely with Mercy for Animals' legal teams to find a way to get cameras inside farms to document abuse.

"We love busting animal abusers. If they want to take away our rights, having based my entire career on this one thing, there's no way I will sit by as this happens," he said.