Did Oregon miss a chance to catch the Zodiac Killer?

At the scene of a notorious double-murder of young lovers Larry Peyton and Beverly Allan, police paid little attention to Edward W. Edwards and soon eliminated him as a suspect. But if they'd dug a little bit deeper ... (Portland, Multnomah County; 1950s) (For text and pictures, see https://offbeatoregon.com/1305a-peyton-allan-murders-manwiththehook.html)