I just found this thread!

Oh Randi, what a horrible thing to do; stealing an object from a grave... . It is so disgusting, I have no words to express how I feel about this...
I cannot understand how the thief was able to unscrew the cat from the stone... ; maybe next time you can use very strong glue and also screws again (and put glue in the hole for the screw too)

I am so sorry for you, and for John too !!