Nick Vivarelli International Correspondent Sky Italia is launching a high-profile documentary series with international ambitions titled “The Overlooked Serial Killer,” reconstructing a true-crime case that has gripped millions of Italians. The documentary investigates the connection between Elisa Claps, an Italian teenager who disappeared in 1993, and Heather Barnett, a British woman whose mutilated body was found in Bournemouth in 2002.