suggestions on what got one of my hens please.

Looks like a red tail hawk to me, very large, muscular bird, Cooper and Sharp shinned won't take on an adult chicken, Had a juvenile dive one twice last year, didn't even spook the hen. Lost my first just laying 3 weeks hen to a red tail 2 days ago. First for me in 50 years. Left carcass and it fed in the evening, set up a padded ( in case one of my cats get nosy) leg hold trap last night. Fed early today, perched on carcass to gut it, (intestines removed from a half inch hole). Placed trap on carcass, covered with feathers and remoistened to keep them in place. Set up so it basically has to perch on it to feed. Learning curve here for sure for birds of prey. I figure it has fed 3 times, is comfortable and my odds have gone up for this capture now that I have learned its habits. Look at the scene, tracks, feed marks. Is it chewed or cut, large hole or small, shredded or neat like a knife. Studying this will help you decide what did it and how to capture it. Have trapped and snare many critters never one of these. Legal, no. But the state won't pay for the hen, lost raising time, feed and eggs. Need to stop it now. winter will make for a much more hungry killer. I figure I have a couple days yet since the weather is cool. I don't go to bed until 5am do to work, so never see it. We will see what evening or tomorrow morning brings. Yes, I will put it down, it would return if relocated. I will make use of the flight and tail feathers as well as the feet. Good luck to you.
As a note, I use dog proof leg hold coon traps from Fleming Outdoors, They have anything you could dream of for trapping, snaring and keeping hides. Library is another source, full of books on track identification and trapping and preparing hides. Even on mounting animals for display.

Well I am eating crow today, caught my killer. It was indeed a coopers hawk, not my speculated red tailed. We know it took young ones from next door in the spring, the lady said it was at her chickens then moved to my yard when it took my nearly adult hen. SO that explains the small amount eaten in the first 3 feedings, and why it couldn't take the carcass, that hen weighed 3 times or more what that hawk weighed.
By the way, it is legal to protect your stock, try harassing and other measures first according to our DNR. It is NOT legal to mount or take feathers from even road kill. In IN, it is a class B misdemeanor, jail time and a $10,000 fine if caught shooting them for the hell of it. Trap set was successful and the animal, I put it down. No more killing for it, I hated to, but relocation would not work, and isn't a viable solution, It would have beat me back home I am sure. Study the kill and the scene, do what you need to do to protect your investment.

Boy that crow pie is good, needs lots of seasoning though, hahaha

Firestomp, yeah that really stinks. I'm pretty sure that one of the two birds are the original killers in my situation as well. I am not sure if they are the same type of hawk I have not looked into that. I plan on fortifying my PIN to keep the hawks out instead of killing the hawk

Sounds like a plan, I love to free range my animals, DO WHAT IS BEST FOR YOU ONLY, DON'T BE SWAYED FROM YOUR DECISIONS AND WHAT YOU FEEL IS RIGHT. My solution was only done with regret and the need to stop the killing of both mine and my neighbors chickens.I don't even hunt anymore, haven't for years now. I do a lot of photography now instead. I had even questioned my ability to being able to butcher rabbits and quail before I got back into it. I look at it as raising my own food and think no more of it.It is a job, not an enjoyment.That hawk had learned to specialise in the killing of chickens. Up to pigeon size birds are their normal prey.