I agree with the others. its most likely you may have accidentally taken the photos. on that model the up\volume buttons are camera buttons. I have many times accidentally taken photos of myself or the floor or what ever is around me, just by trying to turn the volume up or scrolling up on a website or setting my phone on a desk or in my lap

suggestion...cellphones come with a locking feature. it is found in the settings. setting my phone to lock after so many seconds prevents accidental selfies\photos and pocket \accidental dialing.