  In non-central relativistic heavy ion collisions, \P-odd domains, which might
be created in the process of the collision, are predicted to lead to charge
separation along the system orbital momentum \cite{Kharzeev:2004ey}. An
observable, \P-even, but directly sensitive to the charge separation effect,
has been proposed in \cite{Voloshin:2004vk} and is based on 3-particle mixed
harmonics azimuthal correlations. We report the STAR measurements using this
observable for Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}$=200 and 62 GeV.
The results are reported as function of collision centrality, particle
separation in rapidity, and particle transverse momentum. Effects that are not
related to parity violation but might contribute to the signal are discussed.
