I had better luck with this second beetle, I found in one of my containers that was outdoors over the winter. Really a pretty creature, and I did let it go just in case it was a friend... as it turned out to be. They are large beetles and prey on slugs and wireworms among other things.
Bronze Ground Beetle, aka Bronze Carabid, aka European Ground Beetle: Carabus nemoralis, according to this:
http://www.ukwildlife.net/beetles/ca.../carabidae.htm
https://en.wikipedia.org/wiki/Carabus_nemoralis
We need more of these.
