National Police arrested four people on May 10 who had occupied two apartments in a building under construction in Madrid's Chamartín district.
The four squatters, two men and two women, entered the development with suitcases and belongings on Sunday, May 10. They changed the door locks and tampered with the electricity meters within minutes.
Neighbors already living there alerted the police. Officers from the Citizen Attention Group arrested them inside the properties.
The investigation showed that a building cleaning worker had provided the keys and interior details. The apartments were still in the sales phase.