On the night of January 20, shortly after midnight, the security of a company in Haarlem triggered an alarm. The police arrived and blocked all entrances. The dog handler with service dog Siep entered the building to search. At ten to one, a suspect reported himself, scared of the dog. A second suspect was later discovered by Siep in a small space where he had hidden. Both men, aged 43 and 44, were arrested for further investigation.