Vermont attorney general Charity Clark charged 12 protestors, four of whom were Dartmouth students, with unlawful trespassing during a July 24 sit-in at the Immigration and Customs Enforcement's National Criminal Analysis and Targeting Center, a surveillance facility located in the White Cap Business Park in Williston, Vt. All 12 pleaded not guilty at their arraignment in Burlington, Vt., on Sept. 24.Vermont State Police arrested Henry Dorr '28,…