Ryan W. Routh, 59, an itinerant building contractor from North Carolina, was also found guilty of assaulting a federal officer and several firearm violations. The 12-member jury deliberated for about two and a half hours, following a fast-moving trial in which Mr. Routh chose to defend himself without a lawyer. After the verdict was read in court, Mr. Routh appeared to try to stab himself in the neck several times with a pen. As he was being led out, Mr. Routh’s daughter, Sara Routh, one of several relatives present, started screaming. She yelled vulgarities and told her father that she loved him and would fight to get him out of prison.