A predator amoung us

We had a terrible loss last night. Every night we put our chickens up and lock the doors since last year after we lost so many chickens to a possum. Last night while Jeremy was grilling out we decided we would wait till after we ate to put the chickens up so when he finished eating, he went outside to put them up and dead chickens laid everywhere (in a 20 min time frame mind u). We lost 5. :( I am so upset over this, we were lucky that my lil hand raised Pe' Pe' wasnt one of them, he had a few feathers plucked out and now he is having issuses with coming out of the hen house this morning but other than that he is okay...So what do we do now, we put out the live trap and of course make sure our chickens are up before dark but i dont know how we are gonna catch it....