If stupidity were a felony, ex-county Supervisor George Shirakawa would be spending a lot more time in jail. The new charges filed by District Attorney Jeff Rosen against Shirakawa, resulting from DNA samples found on a political dirty trick mailer, is the latest example. But this brings us to a new problem: Shirakawa didn’t act alone. The pieces were written, designed and printed by others. There must be more DNA out there that identifies those who helped. These folks should be lawyering up right now.