When lawyers think of jury trial objections as an opportunity to school opposing counsel on the Rules of Evidence, they do their clients a very serious disservice.
This is because jury trials aren’t ultimately about what evidence is admitted. They are about who tells the more compelling story. Objections only make it more difficult to keep the jury headed in the right direction.
Even in the heat of battle that a trial can seem to be, lawyers do well if they keep in the front of their minds this fact: the jury has no idea what the Rules of Evidence are, or why they even exist. They just want a story they can believe.
Whether to, not just how to
Josh Camson wrote an excellent post on how to object. What’s equally important is knowing when. Objecting at times other than when absolutely necessary to keep crucial inadmissible evidence out will really hurt you.
When you object, the jury has no idea why you don’t think they can hear this evidence. Then, they don’t get to hear the discussion of whether the evidence should come in. So, what is the only conclusion they can reach about your objection? You fear the result of the question being answered, so you are attempting to hide the truth.
Every time you object, you lose in one fashion or another. Even if you win, (objection sustained) you lose (you are a sneaky lawyer hiding the truth). And if you lose, (objection over-ruled) you lose three times: 1) sneaky lawyer tries to hide truth; 2) sneaky lawyer fails; 3) this evidence must be really important.)
The jury hates these evidentiary time-outs. They want to get on with it. So, as Josh pointed out, anticipate evidentiary issues in advance and handle them in limine. You should strive to avoid needing to object by knowing in advance what’s in and what’s out. If you do that, you shouldn’t find yourself needing to object as to admissibility during trial very often.
Sound apologetic, not triumphant
As for form objections, if you simply must object, try to sound apologetic rather than triumphant. If your tone suggests sympathy with the jury’s plight, they are a lot more likely to forgive you for stopping testimony. They may even forgive you for banishing them back to the jury room so you can vanquish your opponent.
A trial is a storytelling contest. Focus on telling yours well. Don’t object just because you can. If you did your homework, there should be no major surprises at trial. If you didn’t do your homework, objections aren’t going to save you.
I’m going to keep mentioning (and stealing from) this great book until you buy a copy: David Ball’s Theater Tips and Strategies for Jury Trials.