Well, it's hard to say, but if it's pre-cell phone days, your character could always take the physical evidence if applicable. I'm 29, so I experienced some of the pre-cell phone days and I remember carrying around a disposable camera. I was in middle school at the time and that could have been the reason, but it's not preposterous if someone did carry around a P&S (point and shoot) film camera or digital camera. In fact, I used to carry around my camera all the time even in high school and college (still do). I would say forget the normalities, work in the quirk for this character, and have the character carry a camera. There is nothing wrong with it.