This situation poses a special concern due to the high amount of traffic through buildings and offices.
Opportunistic crime occurs when security awareness and crime prevention fall by the wayside.
The best plan is to be a good ambassador for your department and the University. If you see someone who appears lost, out of place, or loitering, approach and offer assistance with directions. If their business is legitimate, you have created a good impression. If it is not, you have put the person on notice that security awareness is a priority. You have also taken the opportunity to get a good description.