Most Criminal Defense Attorneys rarely use polygraph in the most effective way to truly help their client. The use of polygraph to completely exonerate a person is truly an excellent way to demonstrate to a prosecutor that maybe they were wrong. Having worked for many years on both sides in criminal cases I have certainly come to the realization that not every person arrested by the police is guilty. However, most practical Criminal Defense Attorneys know that more of their clients are guilty than they are innocent. The practical Criminal Defense Attorney will usually want to do what’s in the best interest of their client and not what’s best to assuage their monstrous ego as many Criminal Defense Attorneys do.
Criminologists have pointed out in their studies of criminal activity that humans are gregarious, in other words they like to be with other people. They have also found that when committing criminal acts that they like to have other humans with them. Therefore when a Criminal Defense Attorney gets a case he is usually having to deal with the fact that there are other defendants, who may or may not have implicated their client in some way. Many times it is a race to be the first to testify against the others and get a deal from the prosecutor.
The Criminal Defense Attorney who walks into a discussion with the prosecution ill prepared should do so at their own peril. You must face the fact that your client is not going to always tell you the truth. As an old Captain of mine used to tell about talking to convicts, “He ain’t here for singing too loud in church.” The best way to know the truth is to have them polygraphed.
Some times you may learn that your client is not as complicit as others in participating in the crime. Many times the prosecutor will be having his own problems with the case and needs a witness to tie up the loose ends. This may be when you can walk in actually knowing more than the prosecutor. If you go in and tell them the things they know and maybe add a few they didn’t know you will be in a good position to negotiate for a sentence reduction maybe even probation for your clients testimony.
I personally assisted a Criminal Defense Attorney in an egregious capital murder case in this way. The prosecutor used his client as a witness and he got a greatly reduced sentence.