Detective Still Trying To "talk" W Me 6 Months Later

6 months ago I was accused of something I didn't do. The cop asked if I wanted to come down and tell my side. I declined.

Finally after months of silence I reached out to ask what was taking so long with the case. He just gave me cop talk and said these things take time. Maybe 2 more months, but he ended the email w this.

"I know you invoked your rights, but at any point you are more than welcome to come talk to me regarding the questions I have. If there is nothing to hide, providing an explanation could speed up this process and give you a better idea of what I'm trying to make sense of. Let me know if that's something you are interested in. Otherwise, I will contact you once a decision had been made. I don't anticipate it being too much longer, most likely putting us right around that 6-month period."

This is him saying there's no case and he's reached some sort of time limit? Why won't they just close the case?