What killed the pigeon?

We found a pigeon that had been killed in our garden. This was unusual as the breast was eaten (missing), the heart, etc was left and the rest of the body was intact, lots of feathers on the ground around it. We have foxes in the area and lots of wildlife, but normally when a pigeon is killed, there is only feathers left and nothing else.  This was the whole body left without the breast.  The heart, etc, was beside the body.  Was pretty gory.