McLEAN, VA (AP).- Colleagues of a Virginia historian accused of altering a presidential pardon signed by Abraham Lincoln to make it appear he had made a major discovery say he betrayed the trust that had been placed in him. The accused historian — Thomas P. Lowry, 78, of Woodbridge — denied Tuesday that he actually tampered with the document despite a written confession he gave to the National Archives earlier this month. The National Archives announced on Monday that Lowry used a fountain pen with special ink to change the date on a presidential pardon issued by Lincoln to a Union army deserter from April 14, 1864, to April 14, 1865. The date change made it look like the pardon was the last official act carried out by Lincoln before he was shot that night at Ford’s Theatre by John Wilkes Booth. In a phone interview Tuesday, Lowry recanted his confession and said he offered repeated denials to Archives investigators