Answered by Ustadh Salman Younas
Question: Is serving on jury duty impermissible because it involves judging another human being that may be innocent?
Answer: assalamu `alaykum
The basis is that serving on a jury is permitted.
If a defendant is innocent in your view, you can, of course, choose to argue such when deliberating on a verdict with your fellow jurors.
Additionally, not all jury services are the same: for example, in a grand jury, jurors simply decide whether criminal charges should be brought against a defendant or not as opposed to actually deliberating on the innocence/guilt of the defendant.
Salman
Checked & Approved by Shaykh Faraz Rabbani