Regarding the dates of the photographs...I believe it was Robert Brown (please correct me if I'm wrong) that testified that the exif data in photo files shows the original date, time, and which camera (even down to the serial number in some cases) the photo was taken with. I would think that if the nekkid pics from June 4th were actually from an earlier shoot that the police would have uncovered this and we'd know already.
JMO
I believe that Melendez testified that all the nudie pics recovered were thumbnails (JM asked him why some were blurry), that is why some have a timestamp and some don't.