FORT MEADE, Md. (AP) — A former CIA contractor who helped design a harsh interrogation program following the the Sept. 11 attacks sought Friday to minimize the severity of techniques used on the men facing war crimes charges for their alleged roles in the plot.

John Bruce Jessen, testifying in public for the first time about an interrogation program long shrouded in secrecy, told a military court at the U.S. base at Guantanamo Bay, Cuba, that the techniques used against detainees had been shown to have no lasting effects and were used only a small portion of the time they were in captivity.

Je...