I feel for you! I had to stay up for 4 nights running because of a black bear after my pigs and chickens. Luckly I can shoot them here. You've done the right thing with the electric fence. They can 'smell' the electricity and won't bother it unless you have a young bear that is. How many lines of the wire did you put around the coop? I run 4, always. That way you keep out the big and the small. A motion light can help as well. If nothing else if it comes on, you know there's a reason and can check.I woke up at 7:30 christmas morning to find my rooster all loopy wandering around the backyard wobbly. Couldn't figure out how he got out (looking thru the window in the back door) until I saw the HUGE gaping hole in the side of the coop. Yeah my rooster survived, and 2 of his lady's and 5 of his children, but they got 8 of the adult females. He must have fought for hours. After picking up what was left of the eight, lets see, heads, legs/thighs he ripped off the body, and the wings, I buried them. Only to go in and take a shower to get ready for family that was coming over to eat. Before the snacks were served he was spotted in our front yard, then as we were starting to eat our christmas dinner, there he was in the front yard again. Ok, we live in Florida, so most of our lives are spent on our huge screened in front porch, great view of the ONF. The coop is not more that 50 ft from our backdoor. Before the day was over the bear had been spotted around our house a total of 5 times. We can't kill him, its not legal here. They say to lock up your chickens, and your garbage. Ok, understandable, no problem we have been, but this bear ripped the whole section of the wall down and just had a feast I guess. Today we got an electric fence, says its enough for a bull, we got the 25 mile package, to do a 10X20 coop. The chickens have been living in the house the past 2 nights, tonight is there first night back out there. I hope the fence works. I kept hoping I'd hear him squeal or something when he went back to check it out, so far nothing. I keep checking on them with a flashlight from the back window. I can see all of them sleeping peacefully. I know I can't keep watch all night, and I don't know what will happen if I wake up tomorrow and have to re-live that all over again. I will be looking for rock salt or something for the shotgun I guess. They say I can't kill him, but I'm guessing I could start puttin' a hurtin' on him every time I see untill I just don't see him anymore. So anyway, thanks for letting me vent, some how it does feel better.
Fianlly, call the game wardens. You've had a loss and they have to respond or you can take matters into your own hands, but first call them and report the loss. Dumb question, but did you happen to take pictures? I know I didn't the first time I had problems with the bear trying to get at the piglets. I did the second time though and it helped me make my position with the authorities. They have to respond and remove the bear, don't let them give you a run-around. Call and keep on calling until they do something. If they are slow....talk to your local paper or TV station. Nobody likes bad press.
I wish you the best and hope this is resolved soon for your peace of mind.