$K\to 3 \pi$ decay results by NA48/2 at CERN SPS

The NA48/2 has collected the largest amount of $K\to3 \pi$. The charge asymmetry parameter $A_g$, sensitive to CP violation effects, has been measured with a precision of $10^{-4}$ (preliminary) both in the three charged pion mode ("charged" mode) and in the mode with two neutral pions in the final state ("neutral" mode). The Dalitz plot structure in the "neutral" mode will be discussed to point out the effects of the charged pion rescattering. The new preliminary measurement of the Dalitz plot parameters in the charged mode will be presented