Thief trap

A thief trap is set up in forensics either to find a perpetrator in a large number of possible theft suspects , or to catch the thief or thieves at a location where thefts have already been committed repeatedly.

As evidence, chemical substances are applied to the object to be secured that are accepted by the perpetrator, his clothing or other objects and can later be chemically detected. The chemicals used are organic-based substances ( ninhydrin , rhodamine B, phenolphthalein ) and inorganic-based ( silver nitrate ) or artificial DNA (as part of a DNA property marking ).

If a theft of gasoline , diesel or heating oil is to be investigated, an indicator is added to the liquids that is not originally contained in these products.

Under criminal law, the seizure of the exposed object (read: from the perpetrator's point of view, the " theft ") does not constitute a completed theft according to §242 StGB , because the trap-setter agreed to the transfer of the perpetrator to the change of custody of the crime object (read: to the "theft" agreed ). Only the securing of the prey by the perpetrator should no longer take place. However, the perpetrator was determined to act, which is why the necessary resolution was not lacking. As a result of the consent, however, a criminally significant removal of the thing, the indispensable act of theft, is objectively impossible, criminal liability for an unsuitable attempt can be recognized.