I am a security technician and systems surveyor (Intruder Alarms / CCTV & Access Control) for a very large UK security company, I wholeheartedly recommend the use of smartwater and the locks mentioned in this thread, I would also suggest the use of a monitored alarm system installed by a National Security Inspectorate (NSI) or the SSAIB member company or the very minimum a system that communicates to a mobile device as audible alarm only systems are next to useless unfortunately.
https://www.nsi.org.uk/
https://ssaib.org/
CCTV unless monitored is a very reactive method, I find that scumbags now expect CCTV and mask /hoodie / scarf up etc accordingly and unfortunately this is therefore inadmissable usually as the to identify an individual the require to be 120% of the monitor size, also avoid analouge cameras such as 700TVL , as High Definition Cameras of between 2 and 4 Megapixel are availble quite cheaply.
https://www.cctv-information.co.uk/i/Guidelines_for_Identification
I am happy to give free advice if required
Cheers
Steve