Texas Lie Detector Test as Evidence
Lie detector test or polygraph examinations as they are officially called, often come up in criminal cases. The police will use polygraphs as an investigative tool and administer them to suspects who deny involvement in crimes. Usually a police officer who is also a certified polygraph operator administers the test. If the suspect fails the detectives will immediately use the failed test in their interrogation and attempt to get an admission from the suspect.
In Texas polygraph examinations are not admissible in court. Neither the State or the Defense can get the test results into evidence. The courts in Texas have ruled that polygraph test have not been proven reliable enough to be admitted into evidence.
Lie detector test can still be very valuable in when defending a criminal case. Criminal attorneys often hire their own polygraph examiners to administer polygraph test if there are fact issues that can be accurately tested. The examiner is hired as part of the defense team just like any other expert. The criminal lawyer should make it clear in paper work that the polygraph examiner is being hired as an agent of the lawyer and that his or her work is covered by the attorney client privilege and work product.
Each individual test differently and each case has unique facts which can effect a test. If there is a favourable test result the criminal attorney can use the polygraph examination to the clients advantage. Some prosecutors will review polygraph test with an open mind and a criminal lawyer can use the test along with other favourable information to persuade a prosecutor to dismiss a case or dispose of it in a favourable way.
Some prosecutors offices allow criminal lawyers to present a defense packet to a Grand jury for review. A favourable polygraph examination can be included in this packet and can often be a key evidence the Grand Jury can use to No Bill a felony case.
If you are or a family member are requested by the police to take a lie detector test consult with a criminal lawyer before agreeing to do so. Only a criminal lawyer can properly advise you on the dangers or benefits of taking a polygraph test.