I recently attended a large event with a room filled with lawyers and judges.  One of the award recipients made the mistake of telling the audience that his acceptance speech was going to be quick and short.  It wasn't.  Judges started to talk amongst themselves, glad-handing politicos started working the room and lawyers pulled out blackberries under the table.  So many attorneys bowed their heads that I thought it was a moment of silence or prayer.  Ultimately, the speech was well written but the speaker broke his promise to the audience.  

The event reminded me of how often a trial attorney tells the judge and jury that they have "one last question" or promises to be "brief" on rebuttal or re-direct.  In the history of jurisprudence, no lawyer has asked that 1 question.  I exaggerate, but it rarely happens. My guess is that every lawyer, before becoming a lawyer, watched a Hollywood movie in which Tom Cruise or Gregory Peck asked permission for "one last question" followed by a scripted, perfect answer. 

There are a few problems with saying you only have a single question or that you are interested in brevity.  First, you should never start by suggesting your examination should be limited by a certain number of questions.  You may have 50 questions depending on the witness' answer!  Take the time necessary  -- don't self-hinder your ability to fully question a witness.  You don't need to rush the witness off the stand.  There is no stop watch.  Second, the jury will be annoyed with you for not keeping your promise.  After asking your inevitable 2nd question, 3rd, 4th …  a bored juror will start to count the number of questions.  That juror will invariably find other jurors to participate in the counting game as your trial continues.  Manage the jury’s expectations with your advocacy not how much time you expect to take. 

Take your time and ask as many questions as you need.