Access into the Washington Navy Yard’s Building 197, where a shooting rampage in Washington left at least a dozen people dead Monday, includes a security clearance check and vetting by contract-hired “visitor control technicians,” contract records show. Authorities have identified Aaron Alexis, 34, a Navy veteran, as the dead gunman. While it’s unclear how Alexis got into the building Monday morning, the Associated Press reported that he may have used someone’s identification. In April, the Navy hired Kansas-based contractor Transtecs Corp. for “visitor control office support services” at the Washington Navy Yard, according to the government’s online procurement database. While…