A theory of the case is a clear, orderly statement an attorney uses to organize her thoughts about a case so she can present it effectively in court. It provides the key justifications she will use to argue the matter in court and creates a blueprint for deciding how and when to present material. This statement offers guidance throughout the trial, from the planning stages to the closing statement. It helps the legal advocate present a compelling case with the goal of a favorable outcome.
Without a theory of the case, an attorney might present an unfocused, unclear case in court. His arguments may appear out of order, or the evidence will not support the arguments. The closing statement will not reiterate the information he laid out, because there is no order to how he presented the material. This can result in a very weak case, and in a complicated legal matter, the judge and jury may decide in favor of the other attorney.
To formulate a theory of the case, an attorney will sit down and brainstorm. She may list out the facts of the matter, including all indisputable information. She may also consider any relevant laws and common sense factors that might play a role in the perception of the information she will present. If police found her client with a bloody ax standing over a body, for instance, the facts are indisputable and common sense would lead a jury to conclude her client must have committed murder. The theory of the case should also consider emotional factors; perhaps the client was in an abusive relationship and may have been acting in self defense, for example.
Using this information, the attorney can prepare a clear theory of the case, a statement laying out the arguments he will use to support his position. Defense and prosecution attorneys can use this technique to create a focal point and stick to it throughout the trial. The theory of a case will determine which arguments the attorney presents and can also play a role in deciding the order of witnesses and evidence presentations. The attorney might want a witness with profound emotional impact at the end, for example, to leave the jury with those thoughts rather than dry, technical testimony about the facts.
The length of this statement depends on the complexity of the case, but it is generally brief. An attorney should be able to boil it down to key points that will create a firm framework for presenting the case in court. With this statement to map out the trial, the attorney can also formulate a closing statement to repeat these points and compel the judge and jury to agree with them.