He had tried to lure a girl home with him after he left parents evening at the school,so he had clearly planned to abduct a child. The extent of the clean up at his home also proves he knew what he had done. He worked at an abattoir and is said to be skilled with knives. A collection of knives were found on his hearth and a charred boning knife was found in his woodburner along with fragments of a childs skull. I can see why he is lying to April's parents in that he can't remember what he did with her body. The truth is obviously too horrific.