Where Stolen Purse Was Discarded: A mist-shrouded bridge on Superior Rd. across the Huron River where the three youths who admitted killing Nurse Pauline Campbell said they threw her purse was visited early this morning after the teen-agers confessed to the slaying. At the scene (left to right) are Ann Arbor Police Lieutenant Walter Krasny; William R. Morey, 18, admitted striking the fatal blows; Patrolman Robert Robinson; David L. Royal, 17, who took part in the robbery-slaying; State Police Detective Joseph Liebherr (behind Royal); and Capt. Rolland Gainsley of the Ann Arbor Police Department. A tip by a Michigan State Normal College sophomore led to the arrest of Morey, Royal and Jacob M. Pell, 18.