This is "Esmeralda", who I found on a hiking trail at night and kept alive as a neat pet for a few weeks. This picture might be misleading... she mostly liked small to medium sized snails; she only went for this one after I laid it on its back with the aperture facing up. I'm not entirely positive she succeeded in feeding on it, because the snail seemed to do a good job of retreating far back in the shell, but she tried. She also ate molasses and banana.
Like other S. viduus I've handled, she made loud, raspy stridulations with her abdomen.

This seems like a good place to mention, this is the only species of carabid that has ever injured me in any serious way. When handling another female individual, I made the mistake of letting the elytra rest against my forearm for a few seconds. Within minutes I was experiencing intense pain, almost to the point of tears. Over the next few days, a purple scar developed, which eventually bubbled up and peeled off over a couple of weeks. Nearly two months later, I still have traces of it left. So be careful!