There are so many important reasons to keep cats indoors. Deranged psychotic cat murderers are just one of those reasons.

Some people think their cats will be happier if they're allowed outdoors. Some people don't like litter boxes and want their cats to go potty outside. These are not valid excuses. Outdoor cats get killed everyday. Even if you live out in the country in a secluded area, your cat could still be attacked by another animal, shot by a human during hunting season, or hit by a car (even if you don't consider your area to be "busy" traffic-wise).

If you love your cat, keep it indoors!