If I remember correctly the Boston bombers were identified by video of them carrying backpack(s) into the area.
Yes, and one of the victims - who lost both legs - identified one of them in a photo.
BTW, didn't Oswald quietly leave the scene too? I've read rumors about that. Something about leaving work without permission. Then found in a theater about an hour later with a loaded revolver and extra bullets.
Or was that Warrren Commission CIA/deep state lies?