Margined Leatherwing (Chauliognathus marginatus) 2012-5-12 Newark Oaks, DE

One of several species of beetles called Soldier Beetles.
http://bugguide.net/node/view/409022/bgimage
for the variety found in the Margined Leatherwing see also:
http://chicagowildernessmag.org/issues/spring2005/soldierbeetle.html