SAINT-JEROME, Que. — Guy Turcotte says the reason he didn't kill himself with the knife used in the stabbing deaths of his two children is that he couldn't find it. Turcotte is on trial on two charges of first-degree murder in the slayings of Olivier, 5, and Anne-Sophie, 3. Crown prosecutor Rene Verret cross-examined Turcotte today and asked him why he didn't have the courage to stab himself once after stabbing the children a total of 46 times. Turcotte replied that he looked for the knife but couldn't find it. Verret then said a knife was found under Olivier, who was in his bed, but that part of it was visible, and that another knife was found on the edge of a bath in a room adjacent to Turcotte's bedroom. While Turcotte, 43, has pleaded not guilty to the two murder charges, he has admitted to causing the children's deaths.