Is Tigran Really a Serial Killer?

Tigran was a weird loner type, unhealthy obsession with all things lewd and kept a knife collection for some reason. He stayed late at the library most nights and if he wasn't at the library he was night jogging as he put it. A sketch artist drawings of the suspected attacker looks almost exactly like Tigran's face. "I didn't want to just pick up the phone and call 911 on the guy just because he was a night owl who looks similar to a sketch"