For all I know about law (though not from the United States) evidence of some sort must be provided by the accusing party. For all I know from what you've been graciously sharing with us, Sergeant, it seems there isn't any (as talk about lost evidence doesn't count as evidence). I believe you are doing great so far.
Although finding a motive for you being framed wouldn't do you any bad, either.
Sounds like (in the words of SSG McCoy) a classic case of "bitches be crazy".
Wishing you the best of luck with this issue!