Martinez checked the site, and at the same time gave Doyle and Bonaby a crash course in pit bull training.
Near the back porch of the house was a water tank about six feet deep. Martinez explained that to increase a pit bull's stamina, a trainer will place a dog in such a tank, forcing the animal to swim or drown; often, a weighted collar increases the degree of difficulty. Martinez found just such a collar.
He also spotted treadmills on which dogs will run for hours at a time, and weighted pull-harnesses that resemble crude Nautilus machines. And he located spring poles that are hung from trees and used to strengthen a dog's jaw muscles. When the dog bites down on the device, he is suspended in the air as he refuses to let go.
Inside an oven in the garage, Martinez discovered a handwritten list with Davis's initials, charting several dogs' pedigrees and win-and-loss records.
Most alarming was a shed near the back of the property. Dried blood stains spotted the walls and the carpet. Martinez also observed that most of the remaining dogs were covered with scars on their heads and legs. He concluded that not only had Mark Anthony Davis been training dogs at Rebel Kennels, he had also been fighting them there.
To Doyle and Bonaby, that information seemed significant. Over the next six weeks, the homicide detectives continued to question Davis about the double murder at his house.
"We believed that the deaths had something to do with his business," says Doyle. "So that meant that whoever had killed his two employees had probably actually been after him. We warned him that he was still possibly in danger. But this had no effect on him."
Despite Davis's refusal to cooperate, the detectives kept working the few tips that came into the homicide office. Although each new lead brought the investigators to another dead end, all were connected in one way or another to dogfighting. Several tipsters mentioned a possible deal that Davis had been involved in with "a man from up north."
The detectives were stymied. Says Doyle, "We really couldn't just go search up north."
Meanwhile, the SPCA's Martinez was working the dog angle. The more Martinez investigated, the more he became convinced that Mark Anthony Davis was very serious about his dogs.
In the world of pit bulls, says Martinez, there are three levels of dogfighters. The first is the street fighter -- the knucklehead who has a couple of dogs in his back yard and doesn't observe any rules. Like some Ken-L Ration spokesman from hell, he simply thinks his dog is badder than your dog.
The second level comprises gamblers who may own a few pit bulls but are not totally consumed with dogfighting.
The third level -- the level where Davis seemed to belong -- is a full-blown, very organized and secretive subculture that transcends race, educational, professional and economic backgrounds. The participants produce their own journals, with names such as Your Friend and Mine, Sporting Dog Journal and Game Dog Times, in which they report the results of matches and advertise for stud services and the sale and training of dogs.
"It's a giant industry," says Martinez.
After HPD ran a routine check on a national criminal-information database, the police found that Davis had been rounded up with other third-level dogfighters in 1993; the Michigan authorities who made the bust called the aborted gathering "the Super Bowl of dogfighting."
Acting on a tip, Saginaw County lawmen had watched as dogfight aficionados gathered at a shopping mall parking lot in a suburban part of the county. From there, the group was transported by bus to a dogfight "convention" -- the site of which was known by only a select few before the match.
"No one just walks into a dogfight," says an investigator. "Only one guy knows the location. People are sent to various other locations and then are called at the last minute. If they don't think you're right, you don't get the call."
The conventions have the air of a county fair on the skids. There is food and drink, and there may even be musical entertainment. But the main attraction is the fights.
Prior to a match, the dog owners meet and formulate a "contract," in which they agree to have their dogs fight in a certain weight category. When the agreement is signed, both sides put up money that will be forfeited if one of the dogs does not come into the match at the specified weight.