A letter laced with the lethal toxin ricin arrived at the Thomas S. Foley Courthouse last May in a stolen envelope emblazoned with the name of a major law firm in downtown Spokane, according to court documents. Matthew Ryan Buquet, 34, has been in federal custody since a few days after mailings that tested positive for the castor bean-derived poison started showing up at the courthouse, a Spokane post office, Fairchild Air Force Base and the White House mail facility. The courthouse letter, which read, “We have a bomb placed we are going to kill you! Hezbollah,” arrived in an envelope from Lukins and Annis, according to federal court filings.