The NA48/2 experiment at the CERN SPS has collected the largest sample of kaon decay into 3 charged pions, with the main goal of measuring direct CP-violating asymmetries in the Dalitz plot slopes. The experiment used a novel technique employing two simultaneous kaon beams with opposite charge, to exploit cancellations of spurious asymmetries and reduce systematic effects. First results, based on data collected in 2003, are presented.