The Truth Serum and Clark's Mutism

The truth serum prompted melvin renald's confession to every christian's murder, but it didn't appear to have the same impact on richard clark. A doctor at the saint josef state hospital called clark a professional face who knew how to fool people into thinking he was suffering from a significant mental illness. He remained silent after his session, often spending his days lying unresponsive on the floor of his cell. When asked if he followed the command, clark replied, some times, i think i did.