The Mossos d'Esquadra warn: thieves use transparent threads to check if you are home

Thieves place transparent threads or small pieces of plastic on doors to know if someone is home. This practice, detected by security forces, is used to plan burglaries more precisely and avoid encountering people inside.

If any such marker is detected, it should not be handled and the Emergency Service 112 should be alerted immediately. This recommendation was made public by the Mossos d'Esquadra through their social networks on August 17, 2026.

How do the threads and markers on doors work?

Why do thieves use these transparent threads?

This method allows discreetly checking if a door has been opened or if there is movement inside the home without direct interaction. The thread or plastic sticks to the door, and if it disappears, it indicates someone has opened the door.

What shapes can these markers have?

They are usually very thin, transparent threads or small pieces of plastic placed in less visible areas, such as the door seal or the door frame itself. Their subtlety often makes them unnoticed at first glance.

What measures should be taken when detecting a thread or marker?

What to do if you find a thread or plastic on the door?

The main recommendation is not to handle the thread or try to remove it to avoid losing evidence. You should call 112 immediately to report the suspicion and wait for the arrival of the police.

What additional precautions can be taken at home?

It is advisable to periodically check the door and its surroundings to detect any strange element. It is also wise to inform neighbors and family to increase collective vigilance and prevent thieves from acting undisturbed.

Source of the article: Mossos d'Esquadra