Breaking News
More () »

I-Team: Former officer shares experience working undercover as dogfighter in Missouri, Illinois

Recent dogfighting bust in north St. Louis County shows Terry Mills the industry is still 'a secret subculture'

HANLEY HILLS, Mo. — A high school football coach.

A registered nurse.

A special needs teacher.


And now an auto body shop worker.

All are professions Terry Mills has seen moonlight as dogfighters during the more than a decade he has spent investigating the crime for the Missouri Highway Patrol and now the American Society for the Prevention of Cruelty to Animals.

“It just goes on and on, they come from all walks of life,” said Mills, who spent more than a year undercover as a dogfighter about 12 years ago. “It transcends all social and economic status.”

His work was part of the largest dogfighting bust in the country’s history oftentimes called the Missouri 500. The 18-month investigation culminated with the rescue of more than 500 dogs in multiple states in 2009 – most of them in Missouri.

Mills, now the Director of Blood Sport Investigations for the ASPCA, was sad to hear about the STL 13 case all these years after his big case.

RELATED: Man charged after police find alleged dog-fighting ring in north St. Louis County raid

But not surprised.

“It’s hard to say that it will ever stop because of that passion that the dogfighters have, but if more people report what they see, it certainly can be curtailed,” he said.

So, how do anti-cruelty laws in Missouri and Illinois measure up more than a decade after the Missouri 500 case?

And, why does dogfighting keep happening?

The Animal Legal Defense Fund has ranked states’ anti-cruelty laws for about 16 years.

Illinois fell to the state with the second-best laws on the nonprofit’s list in 2021. Missouri has always landed somewhere in the middle; in 2021, it came it at 34th on the list.

Here are the plusses and minuses the organization gave each state:



  • Felony animal fighting provisions for all species, and animal fighting is a RICO offense
  • Other agencies or departments have a duty to report suspected animal cruelty
  • Protection orders may include animals


  • Post-conviction forfeiture of animals is not mandatory for those convicted of animal cruelty offenses
  • No immunity for civilians rescuing animals from unattended vehicles



  • Court is required to order post-conviction forfeiture of an animal if the offender is likely to reoffend
  • Sentence enhancements for repeat offenders


  • Social services professionals are not required to report suspected animal cruelty
  • No mandatory post-conviction possession ban or psychological evaluation for people convicted of cruelty
  • Has an ag-gag law, which could help protect whistleblowers exposing cruelty in the agricultural industry

The rescue operation

In the STL 13 case, Brian Maclin, 58, has been charged with 13 misdemeanors and one felony.

The day police raided his property, Maclin made comments about how he liked to fight "featherweights" or smaller pit bulls, according to Maj. Ron Martin with the North County Police Cooperative. 

He surrendered ownership of his dogs to the St. Louis County Animal Control Center, where a rescue group is now trying to save them.

So far, the rescue group has placed three of the dogs in foster homes.

The leader of the organization did not want to share her identity or the name of her organization because of safety concerns.

“I've heard from several people that these dogs are expensive dogs,” she said. “People are not ones to just give their dogs up and let it go. 

"I don't want anyone to know where the dogs are, what rescue they're with, what anything about it at all. Just know that they're safe and there's people working behind the scenes all over trying to get the rest of them to safety as well.”

Mills said she has good reason to be fearful.

In his investigation, he said one dogfighter sent his associates to the St. Louis Animal Care and Control Center to break in and they stole the dogs back.

“These dog fighters obviously do consider these dogs valuable, and will do whatever they can to get them back,” he said.

The 18-month investigation Mills was involved in as an FBI Joint Terrorism Task Force investigator resulted in 100 arrests. He now trains officers around the country on how to investigate the crime.

The last time he was in the St. Louis region was in 2013 when he taught a class at the police academy. 

He spent more than 30 years with the Missouri Highway Patrol, much of it undercover investigating narcotics, terrorism and gang-related activities.

During the 15 months Mills posed as a dogfighter, he trained pit bulls to fight from a property in rural Missouri and attended dog fighting events throughout the St. Louis and Southern Illinois areas.

Mills said dogfighters are motivated primarily by greed, but ego is a close second.

He said he remembers one woman who thanked his team when they showed up to take down her husband’s dogfighting ring because she said he would spend money on dog food and not groceries for the family.

“They all aspire to have a bloodline known to the other dogfighters,” he said. “They're just obsessed with it to the point of not feeding their family.”

Dogfighters compete to have a grand champion dog, which is a dog that has won three to five fights in a row, Mills said.

If a dog loses, Mills said he has seen their owners dispose of them or kill them in unimaginably cruel ways.

“We began the investigation with cultivating sources, and such and obtaining who and where the dogfighters were, and where they were, and to our surprise, they were everywhere,” Mills recalled. “It was just such a secretive subculture, and it stayed in the shadows.

“No one talked about it. No one reported it to law enforcement with any consistency at all.”

Signs of dogfighting

An anonymous caller reported a pit bull was tied to a tree seemingly all the time in Maclin’s backyard. That led to the rescue of the STL 13 from a small garage not far from him.

Mills said other signs of a dogfighting operation include modified treadmills kept in odd places outdoors or in barns, breeding stands where aggressive pit bulls are brought to mate without being able to bite each other, pit bulls coming and going from a house along with loud gatherings that include a lot of yelling.

Mills said he and his partners watched 86 dog fights during their time undercover.

“When we have a lot of people at the dog fights, they have money and where money is, there's guns, so there's a lot of danger for a law enforcement,” he said.

So most busts involved dog yards just like the STL 13, he said.

Can they be saved?

Ultimately Mills and his team seized 407 dogs in Missouri and Illinois along with 21 pregnant females, who gave birth to 153 puppies.

“We had way more dogs than we knew what to do with,” he said.

And not all of them can be saved, he said.

“I'm not saying they can't be saved with enough money and time, but rarely does any organization have that kind of money and time," Mills said. "Some of those dogs have been in a shelter for a year and a half, two years, because there’s still people trying to bring them around to be socialized and interact with other dogs.”

The head of the St. Louis rescue group working to save the STL 13 said she’s going to do all she can to help.

“So far, the ones that we've taken have presented to be very scared, not aggressive, but they have not had a chance to decompress yet, so anything is still possible,” she said. “We are treating them all with kid gloves at this point. 

“They're far from fine, even though they're at animal control getting their medical and their food and all of that kind of stuff, there's no end for them right now. There's no happily ever after.”

Their former owner is expected to appear in court for a preliminary hearing Oct. 4.

He is being monitored by GPS. He can’t consume alcohol or drugs, can’t have any guns or contact with any of the dogs.

So he can go back to work.

In an auto body shop, while others work to pick up the pieces from his alleged hobby.

To report cruelty, visit the ASPCA's Report Animal Cruelty page or call your local police department.

RELATED: St. Louis Health Department recommends euthanasia for pack of pit bulls who attacked three people, killing one of them

RELATED: Cats, dogs, sugar glider among animals rescued from Clinton County

Before You Leave, Check This Out