I'm sorry, annegg. I think I remember your situation now. You posted before.
To answer your question, no, this is more a police matter, with the threats and harassment, than an invasion of privacy issue. I would look into getting a civil harassment complaint filed, and a restraining order issued.
And I would continue to call the police every time this city employee or any of his friends cause you trouble.
Invasion of privacy involves four separate torts, although some states cover these privacy actions under libel and trespass laws. The four torts are: intrusion on a person's physical solitude (an example would be the use of microphones or cameras to tape private activities - like eavesdropping or peeping-Tom situations) and putting a person in a false position in the public eye (an example would be using a person's photo to illustrate a story on drug addicts when they are not a drug addict - this is similar to defamation and will often bring both invasion of privacy and defamation actions) and appropriation of some element of a person's personality for commercial use (an example would be using a famous person's name without authorization to advertise a product - this also violates a person's right to publicity) and publication of private matters violating the ordinary decencies (an example would be getting private health information and telling people you have a STD).
Reports to the city and reports to the police are your best chances of resolving this issue - with a court ordered injunction a possible remedy to future harassment.