This question generally pertains to the legal context in the US. Reviewing this page I gather that capitalization is used to refer to a specific instance of an item whereas capitalize is not used when referring to the general concept. For example, "a judge typically sympathizes with the defendant in court" in contrast to "the Judge refused to listen to what the Defendant argued, against traditions of that Court".
Is this a good way to think of it? Is such a capitalization distinction only used in the legal world?