An elderly Marshalltown woman is dead, and police have her son in custody. At about 2:15 yesterday afternoon, police received a call that shots had been fired in an isolated Marshalltown neighborhood, on a dead-end street. An elderly woman identified by neighbors as Olga Menter was found shot; she was taken to a hospital, where doctors pronounced her dead. Witnesses say cops took her son, George, into custody and questioned another son, Kenny Menter. Neighbors told investigators many referred to the man in custody as “crazy George.” The family dog was also apparently shot.