American pit bull terriers used to be the quintessential all-American dogs. It's the owner, not the breed. In this case, maybe the previous owner.
What they don’t tell you in all of that is, being as potentially lethal as they are, any pit bull that showed any aggression towards humans, even just growling or barking, was culled (killed) to maintain the breed standard. Happened every single generation
A practical aspect of this policy was that in a staged match in the pit, a handler had to be able to reach in and separate the dogs if necessary without the dogs biting him
Nowadays a lot of pit bull owners ENCOURAGE their pits to be mean, and even without that nobody culls for behavior any more, haven’t for generations.