I hope this message finds you well, present circumstances excluded. The short answer to your question is that you would likely be barred from bringing suit against the police department if this action (or inaction) on the part of the police department took place more than two years ago, due to the applicable statute of limitations
for suing a governmental entity.
The governmental entity also enjoys protection in the form of sovereign immunity to prevent suit against them in some cases as well. This case, which falls, unfortunately within their discretionary authority, would likely be barred based on sovereign immunity.
With all of that being said, you owe it to yourself to speak with an area plaintiff's attorney or two about your case. You would want to speak with attorneys that work in or around the area in which the police station is located. These attorneys may know of other people that have experienced similar treatment and that could join in a suit with you against the department.
Another method of retribution for you may be to contact local media outlets to report this behavior and see if they are willing to run a story on it. Bad publicity is something that law enforcement entities want to avoid if possible.
In summary, there may not be many, if any legal avenues of retribution for you in this case based on what you have told me. I hate to tell you that but I am obligated to tell you the legal reality of the situation. With that being said, it is worth it for you to speak with an area attorney or two just to make sure that they are not willing to at least try to file suit on your behalf based on other local knowledge of others being treated in similar fashion. You may also want to contact the local media as well about this treatment.
Let me know if you have any other questions or comments.
Best wishes going forward.