Cole Tomas Allen of Torrance, California, appeared Monday in the US District Court for the District of Columbia to face federal charges stemming from Saturday night’s armed assault on a security checkpoint at the White House Correspondents’ Dinner. Magistrate Judge Matthew Sharbaugh ordered Allen held pending a detention hearing Thursday. The suspect, who appeared on a criminal complaint rather than an indictment, was not asked to enter a plea. He faces three federal counts: attempting to assassinate the president, transportation of a firearm in interstate commerce, and discharge of a firearm during a crime of violence. Allen, 31, is a Caltech-trained mechanical engineer with a recent master’s degree in computer science from California State University, Dominguez Hills who tutored part-time at a Torrance test-prep company and built indie video games on the side, according to a WIRED review of public databases , which revealed a minimal online presence.…