Chlaenius tricolor.
Photo: 03/28/16, 10 pm.

The typical habitats of this pretty beetle are moist or semiaquatic areas. Vivid Metallic Ground Beetles are medium-sized to large and often have vivid metallic coloration. There are over 50 Chlaenius species in the US. Some of these species lay eggs in mud cells placed underneath leaves or twigs. 
bug guide (this photo):