The present invention relates generally to a clamp for achieving tight miter joints in wood casings or other materials comprising mitered ends. The clamp according to the present invention comprises a first handle and a second handle attached to each other to form a handle member and a first jaw and a second jaw attached to each other a clamping member. The handle member and clamping member are attached to each other in a manner that creates an over center cam mechanism that prevents the clamping member from opening unless the handle member is also opened.