PGO initiated proceeding against KGB member who killed UPA painter Chasewycz in Volyn in 1952. DOCUMENT+PHOTO Ukrainian Prosecutor General's Office (PGO) has initiated an investigation into the murder of OUN/UPA (Ukrainian nationalist organizations that participated in liberation struggle against the USSR in 1940s and 1950s) painter Nil Chasewycz by USSR State Security Service (KGB) officer Borys Stekliar. 103 394 246 Ukrainian Politics