The Mysterious Mouse Murderer of Waterloo

You'll forgive me if I don't add a photo to this post...
Imagine my surprise yesterday as I walked through our living room, when something caught my attention. There, sitting atop a pile of sheet music on the piano was a mouse, deader than a doornail! It was clear that he had recently been murdered, but by whom?
I rounded up the usual suspects - three in total. Of course, at least one of those 3 might somehow try to pin the crime on our son Robb, taking into account his amazing appetite. What the perp forgot was that Robb left for the States last week. Nice try.
That left just the 3 felines. Two were quickly ruled out: Lily, at age 18, probably doesn't have the energy to think about a mouse, let alone attempt to kill one; and Big Max (or B.M, as we like to call him), who certainly has the size and look of a killer, has all the brainpower of the mouse - the dead one. He wouldn't know where to begin, going after big game like this.
So, that left a single suspect: the wily, young Gina, already well-known in the family for her skillful stalking of flies and small spiders, all of whom make tasty snacks (or so she tells us). It is interesting to note that, for two hours after the body was discovered, there was no sign of her anywhere. Apparently the criminal does not always return to the scene of the crime.
Later in the day, I made a citizen's arrest. Her sheepish look told me all I needed to know.
I think she's planning an insanity defense plea. Regardless of the sentence she receives, I'm sure she will simply sleep it off. Cat criminals are like that...