Many companies have policies that prohibit unauthorized photographs on company premises. Check your own company's policies, and if there isn't one, suggest strongly to management and HR that the company institute one.
I wonder about this person's mental health. Most of us don't go around setting up hidden cameras on coworkers. Of course, do not insinuate to HR or anyone else that he has a mental illness. That will create additional issues.
Request that management and HR provide you with direction on safely communicating work-related information with this person such as the truck mileage. If this continues to be an issue, consider requesting a cubicle reassignment, telework for one or both parties, greater HR involvement, etc. Make sure management and HR do their jobs in managing this person and keeping the workplace safe and productive.