When I got home to a very relieved dog (thanks, Robbin) I checked quickly that the house was ok (laptop & TV still there?) and then went to close the back door. It was in the laundry room that I noticed some stuff had been knocked over. And the feathers.
Now I saw that black feathers were scattered around the door, near the Swheat kitty litter. I went to straighten up the brooms and the clothes rack, and there were clumps of feathers there.

Crime scene 1

There were more feathers by the litter box, and then in the dining room, a horrific amount of evidence

Crime scene 2

I did a quick peek into the office and the bedroom, but thankfully did not spot a body.  Further investigation had to wait, since the Pupper needed a walk.  Mr. Kitty, who is usually screaming for dinner, was suspiciously quiet.
Getting back home, fed the animals, then toured the house.  No body, and the evidence seemed confined to the laundry room, a few pieces of fluffy down in the kitchen and the dog’s bed in the dining room.  Upon closer inspection, the bed was probably where the murder (and subsequent consumption of evidence) was committed.

close-up - blood!

Probable scenario:  Victim fluttered through the door, attracted by the wheat litter; was pounced on, tried to escape by hiding behind the brooms and laundry rack, shedding feathers (wounded); was caught and dragged to the dining room where it was polished off in relative comfort.
But who was the perpetrator?  Not Pupper, who has never shown much interest in birds.  Mr. Kitty has caught birds, and although had some skills as a hunter in his halycon days, has never proved very good at the dispatching part.  There’s a strong possibility that a neighbor, known only as Grey Tabby may have been the murderer/diner.  He is young and bold (has come up on the porch and stairs) although wary of Pupper.
Nobody’s talking

I know nuzzin' I was asleep the whole time.

Ya got nothing, copper. No wits, no evidence. Ya can't pin anything on me.

Another one for the cold case file.