Looking for an old fanfiction

Greetings everyone!

I'm turning to you veteran ff readers for help finding the title of a fic I read many years ago. Basically, Snape survives the war, and despite being a hero, he is still arrested for Dumbledore's murder. He gets sentenced to the Dementor's kiss or something the like (maybe the veiled arch had something to do with it? Memories are fuzzy), H-R-H try to prove his innocence, but he gets condemned anyway.

Fortunately, he is saved at the last moment by the appearance of a phoenix, which was none other than animagus Dumbledore himself.

Sounds like a fever dream, but I'd really like to track it down and reread it, if possible.

Thanks in advance ✌️