They're watching you
In my 20 years as a parole officer, one thing I've learned is that offenders are very observant and know a lot more about you than you may think. A good example is knowing details about your personal vehicle and your driving habits. If you drive to your office and the jail is nearby, you can bet the inmates are looking out the windows and taking note of what you drive, where you like to park and when you arrive and leave.
Case in point: One day I changed vehicles with my wife, who’s a jail administrator. That day, four different inmates reported to corrections staff that someone was stealing her vehicle! This kind of inmate awareness should serve as a reminder of how alert we also need to be. If inmates know where you’ll be and when and what car you drive, that information can be used to plot a revenge attack. You should stay alert to that, take measures to make yourself more unpredictable (see Protecting yourself & your family from retaliation), practice when/then thinking so you’re more prepared to defend yourself when necessary and carry off duty.