From June 1940, the local council sent Straffen to a residential school for mentally defective children, St Joseph's School in Sambourne, Warwickshire. Two years later, he moved to Besford Court, a senior school. Straffen was noted as a solitary boy who took correction very badly. At 14 he was suspected of strangling two geese. At the age of 16, the school authorities undertook a review which found his I.Q. was 64 and his mental age was nine years six months, recommending his discharge.