Island Life by David Slack

I'd say only about half of them are smiling with their eyes (which is a good predictor of it being a genuine smile). That's still pretty impressive.

Maybe they smile because they know that these photos will be used in the media and could influence the jury. Maybe these crims have foresight: project a good image in the mugshot and it might help later.

Or maybe they are just egotists who cannot resist a camera.