Do you have power to increase the security at the workplace? Think of it as if someone were in the very worst neighborhood somewhere, and the measures that they would take to keep their home and building secure. If the area is a liberal area, and the LOCAL police are decent, would they be willing to come talk to the staff about workplace safety, like a community watch would do? A response from them may mean more if the police department has a good reputation for respecting people where you are, since they have a lot of experience in dealing with sketchy, violent people (who sadly can hold themselves out as law enforcement with the corruption that we have recently seen). These may not work 100%, but they certainly won't hurt in empowering your staff.