  Parity-odd domains, corresponding to non-trivial topological solutions of the
QCD vacuum, might be created in relativistic heavy ions collisions. These
domains are predicted to lead to charge separation along the system orbital
momentum of the system created in non-central collisions. Three-particle mixed
harmonics azimuthal correlator is a \P even observable but directly sensitive
to the charge separation effect. Using this observable to analyze Au+Au and
Cu+Cu collisions at $\sqrt{s_{NN}}=200$ and 62 GeV, STAR detects a signal
consistent with several of the theoretical expectations. Possible contributions
from effects not related to parity violation are studied with existing event
generators, which fail to describe the data. Future directions in studying the
effect are discussed.
