The evidence is offered up by the Anglins’ nephews David, 48, and Ken Widner, 54, who are featured in “Alcatraz: Search for the Truth,” a History Channel special airing Monday. The evidence has pumped life into the cold case, and has investigators lining up new interviews and planning to search South America for signs of America’s most notorious escapees. “This is absolutely the best actionable lead we’ve had,” Art Roderick, the retired US marshal who was lead investigator on the case for 20 years, tells The Post. The Anglin family sat on those leads for years because, they say, they were spied on and...