I've been thinking up another one-shot idea, but I don't think it'd be very easy for you to write, Snowman. Why? Because it'll involve quite a bit of military law, which I'm guessing is not your field. It'd be more up DC20's alley or redshocktrooper's.
Anyways, for anyone who's interested, here's the basic plot synopsis - it stars Reiner and Sigrid.
Spoiler for Reiner:
After a skirmish in Rebel-occupied territory, Reiner is arrested for allegedly breaking military rules of engagement, opening fire on a group of Rebel sympathizers without authorization. Reiner insists that he follows the rules to the letter, but his credibility is put under scrutiny due to his friendship with Sigrid, a well-known former Rebel. Sigrid's own testimony on Reiner's behalf is also questioned, due to his background.
Throughout the whole legal debacle, Lotte also seeks to find out the truth, although she tells Sigrid that if she finds evidence that would prove Reiner as guilty, she still plans to show it due to her credo. (Sigrid understands this, as Lotte is following the "justice is blind" philosophy).
In the end, evidence emerges that proves Reiner is innocent, although the trials reveal some unsettling facts about Reiner's conduct and views.
See what I mean by not easy?