I need help. My dog killed a kitten

Okay so I have a 5 year old Rottweiler named Capone and recently got a kitten for my daughter. They were getting along great and playing together for weeks and then all of the sudden Capone turned. He took the kitten in his mouth and shook it and threw it on the floor. Me daughter and I watched him kill our poor little kitty. What would you do? I feel like I can't give him away bc I'll feel responsible if he hurts someone or kills another animal. I don't feel comfortable leaving hi around my 4 year old daughter anymore. He was such a sweetheart and is very well trained. He went to the vet for a check up about a week before we got the kitten so I don't think anything is wrong with him. Help 😭