Bobert, I was an interpretive naturalist for a long time, talking to the public about the native plants and animals in several and various areas. I had a habit of picking up and skinning out fresh roadkill to use in demonstrations. These were animals in the wrong place at the wrong time.

I think you need to consider this snapping turtle a special category of roadkill. Relocating dangerous animals is preferable if you can move them far enough from people and habitations that they won't cause you (or your nearby neighbors) a problem. But sometimes that intersection between people and other dangerous animals (we are dangerous animals) means a choice is made. A turtle the size you describe can easily take off a finger, and could easily kill a cat. The common snapping turtle isn't endangered.

Rest assured, there are still hazards your cats will face, perhaps a turtle you haven't seen. Nature isn't going to let you create a turtle vacuum, or a place free of cat hazards. You've just put your thumb on the scale of the wildlife balance in your yard.

SRS