Le Grand Alibi (2008)

Like every weekend senator Henri Pagès and his wife entertain guests at their beautiful mansion in a peaceful village near Paris. But this time around, things go awry: Pierre Collier, a psychoanalyst and consummate womanizer, is brutally murdered. Claire, his wife, dazed and confused by his corpse, with a smoking gun still in her hand, seems to be the ideal culprit...