In addition to the no trespassing signs at the gate(s), make sure they mention that purple paint indicates "no tresspassing" and then paint a purple blaze on your trees/fence posts. That serves as a legal posting for "no trespassing" here in TN. Paragraph C.2 has the details: https://law.justia.com/codes/tennessee/title-39/chapter-14/part-4/section-39-14-405/
You can keep trying TWRA/State/LEO/whatever for criminal charges but that's (1) unlikely to happen and (2) if it does bear fruit will likely be nothing more than a simple fine and won't stop the problem. Then you're back to pleading with the same folks to issue a second fine and that may take just as long for them to do anything about it as it has the first time.
I suggest you contact an attorney with a reputation for being aggressive. You want someone who's kind of a jerk, not a nice guy . . .someone who loves a fight. You want a pit bull attorney. They can help you with what you need for building a civil case. The above advice about cell-based trail cams, very well hidden cams monitoring "bait" cams for them to take/destroy, etc. is very good. All of that evidence will help with your civil case for harassment, trespassing, destruction of property, and whatever else the attorney can think of.
As mentioned above, a letter from that attorney might do the trick. The perps will need to decide if hunting on your land is worth the legal expense they'll have when you let your attack-lawyer off the chain.