In May 1968, Straffen was moved to HM Prison Durham. Placed in the top security E wing, he was joined by fellow child killer Ian Brady. Crime author Jonathan Goodman wrote that "the shambling lunatic ... is in prison only because no mental institution is secure enough to guarantee his confinement." Many years later, a prison officer recalled seeing Straffen "circling, banging the fence every couple of minutes" and that one fellow officer described him as aloof and hostile: "Never talks unless he has to ask for something. Always on his own".