A Sacramento photography teacher who teaches a course in the history of photography San Quentin State Prison was recently shown a banker's box full of thousands of negatives, all shot inside the prison, mostly of daily prison life, between the 1940's and 1980's. Cal State Sacramento professor Nigel Poor tells criminal justice site The Marshall Project, "My heart just exploded. As an artist, or a photographer, or a collector, you couldn’t wish for a better box of treasures."

According to the Marshall Project:

The pictures, for the most part, are prosaic, like outtakes from a yearbook photo shoot. One shows five members of an amateur rock band. Another depicts uniformed football players gathered for a team photo. In yet another, a man is shown carving an ice sculpture. Occasionally, though, the subject matter is much darker.

One photo comes with caption information: “Martinez Killed in Yard, 1963.” It shows empty bleachers and what appears to be blood spatter in the foreground. The yard is in San Quentin Prison. And once you know that, there is nothing prosaic about any of the photos.

Poor has spent the last four years scanning and cataloguing the images, some of which you can see in the gallery here, and some of which she has been using as part of the class she teaches to prisoners. As the blog Prison Photography reports, Poor still hasn't finished the project, and she estimates there are about 10,000 images in total.

All the photos were shot by prison-appointed photographers, most of them likely corrections officers.

Eventually, she hopes, they will make their way to a state-run museum.