You have an illegal breed of dog.

These breeds have a law against owning it.

I would hope that if anyone saw an illegal activity or saw a neighbor breaking a law that they would first and foremost ALWAYS contact the police and let them investigate and handle it.

I vehemently disagree with your assumption that I should approach a neighbor who is breaking the law or doing something illegal and try to "handle it myself".

I understand your dog was gentle, loving, kind but there is a law. You broke this law. There are reasons for this law. Having said that though, I myself am a dog owner I am very saddened for the loss of your close family member.