The Maastricht police commissioner requested that Salomon Horwitz, Sophie Horwitz-van Spier, Carolina Horwitz and Jacob Horwitz, all residing in Maastricht, be located, detained and brought to trial. They had left their place of residence without the required authorization. This description referred to Jews who had gone into hiding.
Algemeen Politieblad, nr 37, 17 September 1942, 1044, notice 1931
In addition, a Jokos file (number 18636) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.