Good day. Is there a module or quest where the player is accused of murder and must prove his innocence?
Judging from the silence, apparently not.
I thought for certain there were DnD ones for a party to clear the name of themselves or an innocent person. You may have to go to Reddit.
I have played some PFS1 Scenarios where the party went on clue quests, trying to rack up as much evidence and as many reliable witnesses as possible. You could use a point system (hit target X) or a skill challenge (each bit makes some obstacle(s) easier).
Apologies for not remembering any names though.
If building, one could use most any of the many movies that deal with this, like The Fugitive or where elite groups go rogue when framed. The trick is giving the PCs enough knowledge to pursue the next clue/witness/etc. while not leading them down a railroad (or at least not an obvious one). Also beware too many options, or they may get bogged down in decision making rather than adventuring or pushing the plot.
I'd recommend having multiple factions, a mix of allies and enemies. Maybe like obvious good guy enemies the party shouldn't kill (so are weak enough to subdue or when strong the party should escape from rather than confront) and corrupt ones they can kill (like mercenaries who don't know any secrets) plus innocent helpers they should protect or keep from getting caught up in the mess.
And many of these choices depend on how grim you want to get to whether there are clean answers or not.
Not about the players being accused, and not a module, but Book 2 of the Carrion Crown AP is called the Trial of the Beast, where the Beast of Lepidstadt, a sapient flesh golem, is on trial for nigh 20 years of general terror and mayhem. The catch is that certain people in town also recall stories of the Beast acting in kindness and wish the party to see to it the Beast gets a fair defence in the face of overwhelming mob mentality and 20 years worth of scapegoating every ill to the bogeyman.
As an aside, in my opinion the story gets even better if you take a note from the actual Frankenstein book by making the Beast much more intelligent and sophisticated--though in order to avoid giving too much away to your players it also helps to make him act incredibly defeated and depressed.
Runs from 4th - 7th level over the course of hardly 5 days. Fewer if you skip the after-trial where you learn what's really going on by paying a visit to the Beast's true creator