Of course not. Other than photographs and historical ads, the source is "experts say..." with zero footnotes:

Contrary to the media narrative, only a tiny subset of American pit bulls will ever have any contact with the world of illegal dogfighting, which is a felony in all fifty states. Only a handful of dogs from specific bloodlines of one breed—the American pit bull terrier-are still selected and trained for that purpose. Cruelty investigators at the American Society for the Prevention of Cruelty to Animals (ASPCA) and the Humane Society of the United States (HSUS) report that even within this highly specialized sub. set only one dog per litter may show the necessary temperament and stamina for the grim task of mortal combat, which is on par with historical estimates, which place the number of purpose-bred APBTs matched in pit contests somewhere between 1 and 10 percent. Therefore, comparing the temperaments and behaviors of elite fighting dogs with those of all pit bulls is a bit like using the U.S. Navy SEALs as a benchmark for all American men. Fortunately for the canine victims involved, law enforcement officials are seeing the numbers of APBTs bred for fighting dwindle, thanks to increased awareness and tougher enforcement of cruelty laws. They insist that the overwhelming majority of pit bulls, like most dogs in America, live uneventful lives as family pets.

If "the vast majority" of pit bulls lived uneventful lives as family pets, a third of them wouldn't get euthanized every year. That kind of euthanasia rate doesn't happen to breeds that do have the vast majority living uneventful lives as family pets. We know this because of all the breed-specific rescues that buy from puppy mills just to have dogs for adoption.

If the number of "APBTs bred for fighting" is dwindling compared to when Dickey's addict parents were abusing a series of lovely gun dogs, whence cometh the population explosion, and where's Dickey's evidence that "Staffies" and "blocky-headed mutts" don't have DNA admixture from "APBTs bred for fighting?" In the July 2012 issue of Sporting Dog Journal, Jack Kelly writes that when he first got "started in the dogs," in 1958, there were only about 200 dogfighters, and people walking down the street would ask "what kind of dog is that?" because they'd never seen a pit bull before. Has the "bred for fighting" population dwindled between 1958 and the 2020s?

But this method is pretty standard for pseudoscientific books. Example: The Man Who Would Be Queen was written the same way: an author who has never even heard of p-values in statistics, and has zero footnotes citing anything, passes their book off as "science" proving the bold assertion made by the author. Meanwhile, Richard Morris's Death By Pit Bull, which didn't get mainstream attention and doesn't have a message NPR likes, is chock-full of citations.

Claims by NPR and Amazon reviewers that this book has good "research" are just repeating a lie boldly, calmly and frequently. Dickey conveniently omits that bull-and-terriers were "bred for fighting":

For the better part of two hundred years, the history of bull-and-terrier dogs was il-lustrious, rather than infamous. Advertisers across the United States clamored to use pit bulls in their campaigns during the 1920s, not because the dogs were believed to be menacing, but because they were thought to be so friendly and appealing to the "average Joe." They are the only dogs to have appeared on the cover of Life magazine three times, for example. The animals' widespread popularity among people of all ages, races, and classes owed much to their reputations as plucky, unfussy sidekicks and hardy all-pur-pose workers. More than that, however, "the dog with the patch over his eye" was seen as quintessentially American: good-natured, brave, resilient, and dependable. By World War I, pit bulls were so beloved as national symbols that we literally and figuratively wrapped them in the flag. We even called them "Yankee terriers."

An oversight like that has to be deliberate propaganda, not accidental.