Im probably going to get roasted for this but some dogs just go bad no matter what and need euthenasing.
We had 4 Boerbulls when I was a kid, no matter what he was always a little too edgy. All our other dogs were loving and obedient and he was just wild from being a pup. Eventually we had to give him away to a farmer who ended up shooting him after he attacked his wife. He was with them for 2 years before this happened.
On the other hand one of our other dogs became a police dog. Great breed of dogs but like all they can go bad.
Mostly it's in the way they are raised but it can also be in the genes.