GRAHAM, Wash. -- A domestic violence call led to the discovery of what Pierce County sheriff’s deputies said appears to be a training facility for fighting dogs at a home in Graham.

Elijah Peters, 37, was arrested Saturday on suspicion of threatening to shoot and kill his girlfriend during a fight at a Graham home.

Pierce County sheriff’s Detective Ed Troyer said when deputies arrived they found 22 pit bulls tied up in separate dog houses in the home’s back yard, a treadmill fitted with a dog leash and makeshift wooden side panels and other dog training devices.

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Troyer said the panels are to keep dogs on the treadmill during training.

According to arrest reports, several of the dogs showed evidence of severe scarring.

“The dogs are scarred up. It's obvious that they've been involved in altercations and the way that they kept them separate, it's obvious they can't be around each other because they are going to fight,” Troyer said.

A search warrant to seize illegal dog training material was served at the residence.

KIRO 7 reporter Kevin McCarty said he spoke with two men at the house who claimed the dogs were not being trained to fight.

Investigators also said they found 25 marijuana plants that Peters allegedly claimed were for medicinal purposes. Arrest reports revealed that medical paperwork was found at Peters’ residence.

Peters pleaded not guilty to a charge of felony harassment and his bail is set at $20,000.

Detectives are also looking into charges against the people allegedly training the dogs.

Neighbor Howard Johnson said nearby residents have been complaining about the dogs at the home for years, but he said nothing was done until Peters' arrest.

VIDEO BACKSTORY: Neighbors Say They've Been Complaining About Dogs