Dead baby Magpie

For the last year or two, we havent seen much of the magpies. Today, as I did the school run, we saw a baby maggie, dead on the footpath, right next to a tree where we found another little bird, a swallow. I am now wondering if there is a nasty killer bird out there (prolly the Butcher birds) killing off the young. I will try to grab a picture of it. Poor magpies!