Lamb to slaughter
I think that Mrs. Maloney was crazy because she killed her husband with a frozen leg of lamb chop. After she killed her husband she carried on as normal. She went to the store and bought potatoes and peas. When she got home and him lying on the floor she called the police. When the police couldn’t find the murder weapon Mrs. Maloney fed the lamb to the police for supper. They didn’t even realize that that’s how he could have been killed.