Two brothers, Khalid & Ibrahim El-Bakraoui, involved in the Brussels suicide bombings, murdered an elderly man earlier to see what killing was like, according to a Belgian report.
Ibrahim blew himself up at Zaventem airport, murdering 11 people. His brother Khalid left another 20 dead at a metro station.
The pair told fellow attackers they had shot dead Paul-André Vanderperren, 76, on the street at random, De Morgen newspaper reports.