The UK Daily Telegraph, citing German newspaper Express.de, reports that 27-year-old Lubitz may have mixed a drug into Captain Patrick Sondheimer’s drink, causing him to need to use the restroom and consequently leaving Lubitz alone in the cockpit.
Investigators believe that Sondheimer was locked out of the cockpit by Lubitz after the captain left to go to the bathroom. Sondheimer is heard on the cockpit voice recorder banging on the door and demanding to be let in moments before the plane crashed into a mountainside, killing all 150 on board the March 24 flight from Barcelona to Dusseldorf.