2 dead in different ways (in coop), 1 missing, 1 confused flock owner.

We took over an existing flock about 10 months ago, as part of the ranch that we manage. The coop was pretty overcrowded (9 hens, 2 roosters). As the months have gone on, we've lost 1 hen (sickened, and died), gave away 1 rooster, and mostly were just dealing with overcrowding issues - picking at each other's feathers. We started letting them out during the day, and thought that would help solve any of the problems, since we were down to 8 chickens, which was closer to what the coop should have.

Until this week.

1 hen we found dead at dusk under the coop, in the run. She had all her feathers, seemed intact - no part of her eaten. We didn't think to look for a broken neck - nothing noticable. We just thought 'oh well, I guess one died'. We did find the small rooster (a Frizzle) on top of her body, pecking at her.

The next day, we couldn't find one of the hens near dusk, when we bring them in. Assuming the worst, we closed everyone else in, and thought maybe something got her.

The next morning (this morning) SHE was back, wandering up the driveway, but we found the frizzle rooster dead as a doornail in the coop. I have a picture of his body, but he looked.... odd. Almost scalded - picked almost clean of feathers, skin discolored. No obvious tear marks, and otherwise intact body/head though?

We are worried and confused about what seems to be going on. We're consdiering a few options, but are new to the chicken world.

1) something attacked the rooster and the hen, the hen was able to get away and come home, the rooster "got away" only to come home and die?

2) the rooster got sick pecking at the dead chicken, and the other chickens pecked at him (though we didn't see feathers inside the coop, so he must have lost them outside before coming in to die).

3) we do have wood chips down in our flower garden - could this be poisoning them?

4) if it is an animal attacking - why isn't it eating the birds?!



Thank you all for your thoughts.
sorry for the picture, but here is the rooster's body: