Keep checking with the police department on the progress of their investigation
This is not intended to be legal advise or as legal representation. I am a California personal injury attorney . Be aware that every state has its own statute of limitations; and statutes & case laws that govern the handling of these matters.
In Davidson County, the DA's Office has a "warrant screening" process, by which you may go down to the commissioner's office and seek a warrant against someone if the police have only made a report and not taken a warrant. If you are in a different county, you may simply need to go in front of a commissioner (night court, they call it in Nashville), and swear out a warrant personally against the suspects, and list your witnesses on the warrant. Alternatively, in a smaller county, simply call the DA's office yourself and ask them to prosecute, or help you through the process. You can also call the Detective division of the police department, and ask one of them to help you with taking out a warrant. Good luck.
The answers provided on this site, and on our websites, are for educational purposes only. Since every case is factually different, I may need further information to provide the most up to date answers or responses to your questions. Furthermore, this may be construed to be an advertisement from an attorney, and the TN Board of Professional Responsibility requires that I advise you of such. In any event, my responses here do not suggest an attorney/client relationship, nor do they suggest representation in any matter. In order to have legal representation, you would need to set up an appointment. Blessings to you!