I agree about the slide requirement by magazines and again, if he were taking classes it would be required to learn the E6 process, to process Ektachrome slide film. (Kodachrome slide film could only be processed at Kodak-this was the preferred film of magazines, the quality is just so much better in reproduction and there was less room for error by the photographer). So, he could process without anyone seeing him if he was using Ektachrome. Another note, processing slides back then was expensive. C41 was/is the color negative and print process, again very expensive to do at home. I wonder if he had a dark room. C41 was only briefly taught in photography school. There are plenty of his photos that are bad and do not reflect thought, ie. under exposure, slow shutter speeds. He did know enough to shoot some with shallow dept of field so the background would be out of focus and hard to identify. Though, it was stated that in some of the photos the victims were passed and posed. I would think those would raise a red flag at a processing facility. A Polaroid camera might be a likely tool for him no negative and snapshots with one would explain the poor image quality. I believe Polaroid prints do not hold up well over time, if the storage building was not temperature controlled they most certainly would have deteriorated rapidly. Yes, I did graduate with a photography degree, 4 years and I've been a professional photographer and darkroom technician for 20 years.