When providing an answer on law.se is it best practice to cite a written law or ruling in a court case? Or is it adequate to simply "state the facts".
An answer will always be improved by a citation, but I don't think they should be mandatory. In many jurisdictions access to judgments is not free, so it would be a high bar to entry if we demanded that every answer cite correctly.
People can always come along later and add missing citations to answers if that would improve them.
Since law is typically based on documentation, I don't think that requiring references is too much of a burden on this specific SE. In fact, If you aren't able to produce good references, then you probably aren't actually enough of an expert to properly answer the question in the first place.
It shouldn't necessarily be the moderator's job to enforce these kinds of quality conventions, but users should brutally downvote answers that they can't be confident in.
What I don't want to see, however, is the attitude that an answer is correct just because it has references. The important part is that you can have confidence in an answer, and references just a way to facilitate that confidence. There is a lot of misinformation about the law out there, and there are a lot of ways to misinterpret your source references. Answers with low quality references should be treated as though they have no references at all.
I think that a strict references required rule would prevent this SE From becoming a cesspool of opinion on what the law should be, and instead a bastion of information that is both accurate and credible.
The law is hard, and answering questions well here is can be also. Requiring references can help protect us from popular answers to the inevitable hot questions that are what people think the law should be rather than an accurate answer on what the law is that is backed up by references, precedence, and well written arguments on the law.
Honestly its not impossible to back up claims, it requires a bit of effort but a good answer should have that, but too often on popular questions bad answers get up-voted because they have a populist feel. That will be bad for this site. So lets avoid that with a reference requirement for all answers.