Theft is one of the most frequent ways museums suffer losses and may occur in a number of ways, for instance burglary after hours, removal of objects during opening hours, or stealing by employees or visiting researchers.
It will never be possible to prevent the theft of art objects entirely – after all, the whole purpose of exhibiting collections openly is so that visitors can see them close up. It is however possible to make it more difficult for criminals by putting a system of defenses in place encompassing physical, electronic and organizational measures that will enable criminal acts to be thwarted and perpetrators to be caught.
Such measures must always be tailored to the particular collection in question. Depending on the location of the building, the layout of the rooms, the value of items in the collection and the number of staff available, measures should be set out in a security policy and agreed with the building's owner and other users. A comprehensive security policy will also take into account the proportionality of the measures, any existing defenses, and any security recommendations that can be readily implemented.