Looks like a neighbor "liberated" his chickens. Maybe the perp wanted to make it appear that they got attacked by a critter?
This is just down the road from me. There are lots of people around here with chickens and lots of people around here that are not thrilled the neighbor has chickens. Just because someone has a long commute to work doesn't make 'em country folks and in this area, everyone thinks they should have a say in what the neighbors are doing.
This is why we need to be vigilant, Pierce County is looking at banning backyard chickens.