Wow. Move to the country. This is why people live in little shacks making letter bombs, because jerks get to unleash their garbage on us and we have to send them treat baskets and apologies. Jeez, these people don't care about a treat basket, they'll throw it in the trash. Ditto on cookies, eggs, anything... they regard you as filth and sub-human. Find out your laws, have copies of your laws kept in a safe place in your home, get a written statement from the witness, signed and dated, and safeguard your pets. These people will look at their cat every single day and build up even more hatred toward you. They will tell every one who sees the darn cat about what you, the evil neighbor, has done to their harmless little cat, and the story will evolve to something wholly different than what happened. Your mother will be painted as the crazy old lady next door who shoots the neighbor's cat for fun. I can only imagine what will be said of you. This is reality, this is people at their worst. You don't have nice, rational people for neighbors. You have opportunistic, selfish, arrogant meanies next door. It will not improve until they die or you move. Protect yourself. Plan for what you and your mom will do till this dies down, then plan for the next time, as it will happen again. Maybe they'll get another cat to comfort the grieving witch. Or worse, a dog. Prepare. Prepare. Protect.