In many states you can have your vehicle license plate information made confidential. Have that done so that people who try and run your license plate can't get your home address. Many officers have as much of their mail as possible sent to a post office box.
If your agency may have been targeted there are several things to consider. Sometimes police officers or police employees may be compromised. Run a check for warrants on all people who enter your police station to do work, all city employees and contractors. Update background checks on all police officers, and police employees. Sometimes gangsters will target women as girlfriends so they will spy on the police for them. Dispatchers, records clerks, file clerks, parking enforcement, and other non-sworn police department may be spying on the police, stealing records and gathering intelligence for their gangster boyfriend.
Check on your parking lot and lobby security. People who don't park in your parking lot don't need to be hanging out there. Respond units and do field interviews of anyone loitering on or near your agency property without visible lawful business. Good camera coverage of your parking lots, both for your personal cars and the police vehicles is essential. The entire exterior of your station should also be covered by cameras. You may miss a bomb being planted, but at least you will have a record of it once it is discovered or exploded. Cameras are cheap and full coverage is necessary; that's what the SGT Says.