This toothy specimen is Tetracha virginica, a fairly large species (16-25mm), widespread in the eastern United States. This species is a deep oily metallic green; largely active at night when it nimbly forages for prey and is often attracted to lights. During the day it can be found taking shelter under miscellaneous ground cover.
The larvae of this species are large and found in bare patches of soil sparsely covered with grass; often recognizable by their notably larger diameter.
For more information on and photos of this species see the Bugguide page.