You can train a dog to attack on command, to leap for the throat, to love the taste of blood. You can train a human the same way -- that's what the government-sponsored Pit Bull Project was all about. But, even with the most extreme training, humans are less predictable than dogs. And instability can be... deadly.
The government knows that. That's why the Pit Bull Project got cancelled. But that only means the dogs don't have leashes anymore, and they only come out for special occasions.
One of those occasions just came up. The dogs are going out for a walk. Don't get in their way.