Doents mysteriously send to computer recycle bin?

I just looked in my recycle bin and noticed that a bunch of photos from my external hard drive are in there that I did not put in there. And even more odd is that it shows that the date they were placed in there is May of 2007. I know that my computer has the correct date right now and I know I emptied my recycle bin just a few weeks ago. And no one else has access to my computer. Does anyone know how this might have happened?