The four Romainians arrested on the Wallen in Amsterdam last July belonged to a criminal organization that exploited women from Romania and other countries for years, Het Parool reports. The women worked behind the windows in Wallen, which is also known as the Red Light District. Crucial evidence in the case was obtained after the police placed listening devices in the suspects’ vehicles.The suspects’ defense attorney maintains that there is insufficient evidence, which emerged during the first pro forma hearing at the court in Amsterdam-Zuid.