Sounds like you do have some serious issues here as it seems you are now being seen as a target for these thieves.
Is there nothing the local police force can do? Even increased visibility may be of some help to make them think twice.
If your really game you could include that you would be willing to work on those actions and take them up as being your job.
right looks like i've finally kicked things in to gear... as the site manager is too lazy to sort things out and the headteacher is obviously concerned about the recent thefts we're looking into doing CCTV in house, rather than going through that shoddy company "ADT"
Having a look at these at the moment:
Gold Enforcer 4 Camera Professional CCTV Kit - CCTVdirect
That would be for reception, apparently the site manager was quoted £3k and £2k from two suppliers for kit + installation of CCTV for 3 internal and 1 external camera, we're quoting him £1k for using the above kit, also looking at fitting this into another building which currently still records on to VHS tapes!!!....
Gold Dominator 16 Camera Professional CCTV Kit - CCTVdirect
Any opinions on the above or alternate suggestions?
Take a look at Mobotix kit - they demo'd it at the Edugeek conference. Speak to Net-Ctrl (sponsor on here) as they deal with them.
They're IP based CCTV, they do 360 degree view cameras using fisheye lenses and clever software, make use of standard hard disk storage (so a simple NAS would do for recording) and have a bunch of other features.
The cameras a multi-megapixel resolution so are MUCH better quality than standard CCTV, and as such much better for identifying muppets stealing things!