How can I distinguish between dicta and a judgment in US Supreme Court cases?

I know what dicta is, but how can I tell where it is?How can I distinguish between dicta and a judgment in US Supreme Court cases?
Frankie's answer is excellent and I can't think of any way to improve upon it. I guess the best thing that I could do for you is to give you an example of a short opinion which I think is filled, frustratingly, with too much dicta. Here is the famous Palko decision.


http://www.law.cornell.edu/supct/html/hi鈥?/a>





Between numbers 1 and 2 there are nine paragraphs and most of what you'll see in there is just plain dicta. Everything that you read in the opinion which explains WHY the Court rejected Palko's argument (that his right against double jeopardy was violated) is ratio decidendi -- not dicta. And everything else -- the rhetoric which explains what else, besides the Double Jeopardy principle, is covered by the 14th Amendment, is just dicta.How can I distinguish between dicta and a judgment in US Supreme Court cases?
You've just got to read the whole case and determine yourself. Obiter dicta will often be ';what if'; musings or comments that aren't binding, while ratio decidendi is that which forms the reasoning behind the judgment, becoming precedent. The two aren't split up for your convenience, unfortunately, and some parts of the writing will often be arguably one or the other. It can be difficult to differentiate the two at first, but it gets easier after a while.
Usually, the actual decision begins ';we hold that ....'; or ';we find that.....'; or ';In this case, the Defendant is not liable ....';etc....





Dicta is everything else (like the reasoning behind the decision).