Article continues below advertisementA subtle but shivering detail has been unearthed about Natalee Holloway's killer, Joran van der Sloot.In a resurfaced Dutch interview from June 2010, the notorious murderer's mother, Anita va der Sloot, confessed her son used to frequently sneak out of their Aruba home at night.The Caribbean island is where Holloway mysteriously vanished at age 18 on May 30, 2005, during a high school graduation trip.