The trial process is fairly straightforward in America; we have an adversarial trial system which is founded on the presumption that the ultimate truth is reached through a vigorous debate. The thinking goes that instead of entrusting the finding of facts to a single neutral investigator, we can just embrace the human tendency to make snap judgments or bring biases with them into their courtroom. It’s easier to trust someone to be biased than neutral, I suppose.
So we set up two parties on opposing sides, to seek the truth through competition. Like most competitions in our society, however, we don’t allow the competitors to employ every vicious trick they can think of. Partly because there are some really effective tricks that lawyers can think of.
You’ve probably heard the crackerjack lawyers on Law and Order stand up and yell “objection, your honor!” when their opponents say or do something untoward. If the judge remembered to wear her mind reading helmet, or it’s plainly obvious that the other attorney is engaging in shenanigans, the judge can sustain the objection without further explanation. However, most of the time, you’re going to need to provide a reason for your objection.
One of my professors used to be a federal prosecutor. Actually, a lot of them were prosecutors. (Old trial lawyers never retire, they just adjourn more often.) Now they have moved into academia, and they bring fantastic stories from the world of lawyerdom. Now I relate one to the internet.
When you’re trying to convict defendant of a crime, one of your goals is probably to prove that he was at the scene of the crime. In the old days, before security cameras were everywhere, and cell phones could track your movements, this was done by putting an eyewitness to the incident on the stand. Then the prosecutor would get up and do his best impression of Perry Mason.
“Mister Witness, you claim to have seen the brutal attack on the victim at the pier. Do you see the person that attacked the victim in this courtroom?”
During a trial, a lawyer isn’t permitted to speak directly to the jury outside the opening and closing statements. But the opening statement is (theoretically) a preview of the evidence, and the closing statement is a summation of the evidence. So to actually present the evidence, lawyers use witness testimony. ”I saw the robber point his gun at the victim.” ”The blue car ran a red light and hit the plaintiff’s car.” And so on.
A lawyer also gets a chance to discredit the testimony of her opponent’s witness by asking things like “what kind of gun? How far away from the robber were you? Were you behind the victim, or behind the robber? How dirty were your glasses?” or “Were you watching the car, or the light? Where was the plaintiff’s car? My client’s car has a dinosaur sticker on the bumper: did you see any such sticker on the blue car?” Now we get to hearsay.
Hearsay is, briefly, testimony by proxy. The witness is not telling the jury what he saw: he’s telling the jury what someone else claims to have seen. This is problematic for a number of reasons.