Is it forbidden for a scrivener or legal drafter to work for litigants, given the possibility that one of them may be an oppressor or make false statements?

If you write complaints and lawsuits for people as they dictate them to you, and you do not know that they contradict the truth and reality, then there is no sin upon you; the sin is upon the one who stated that. However, if you know that what they ask you to write is a lie and falsehood, then it is not permissible for you to write it, because that is aiding in sin. Allah Almighty says: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression). And you must advise those whose lies you know.