If, when you have completed your risk assessment, you think that
theft (daytime) or smash and grab would be likely you need to review the locks and
alarms on the items of value.
Catalogue the items, photos and descriptions. Use the Getty museum
object nomenclature (ID) system. Valuable silverware etc should be in good solid
display cases with good locks (and possibly alarms).
Paintings should be screwed to the wall where possible using
security screws. Consider object protection systems and CCTV.
Invigilator / staff manning levels and training are also critically
important. There is a good source of advice from ACE.
Remember much theft is opportunist. But some is professional with
art stolen to order. Your security plan needs to cover both possibilities.
An identical necklace to
the one shown was stolen from this museum shop display case (the top was left
unlocked - it's locked and alarmed now!)
Watch out if you plan to
use vibration sensors on laminated glass showcases. The transmission
of vibrations can be quite limited.