The Week 100 Forensic Science Geek of the Week is Announced

The Forensic Science Geek of the Week

Please visit the www.TheTruthAboutForensicScience.com FaceBook fan page.

The week 100 “www.TheTruthAboutForensicScience.com Forensic Science Geek of the Week” honors goes to:Steven W. Hernandez, Esquire

According to our Geek, the following is offered:

Steven W. Hernandez, Esq., is admitted to practice in State of New Jersey and the United States District Court for the District of New Jersey. He specializes in DWI defense. Mr. Hernandez is a member of the National College of DUI Defense (NCDD). American Bar Association, The New Jersey Bar Association, and the Ocean County Bar Association. He has successfully completed the DUI Detection & Standardized Field Sobriety Testing, the same course recognized by the National Highway Transportation Safety Administration (NHTSA), used to train police personnel. Mr. Hernandez was the first attorney in New Jersey to receive his Forensic Sobriety Assessment (FSA) Certificate, by demonstrating knowledge of the science and forensic use of roadside sobriety testing.

Congratulations to our Forensic Science Geek of the Week winner

OFFICIAL QUESTION:

1. What is pictured here?

2. How is it purported to work?

3. Has it been validated?

4. What do the studies show?

Our Geek of the Week answered:

(1) The Horizontal Gaze Nystagmus Test

(2) It is “purported” to work when an officer or other “trained” official holds a stimulus (pen, finger, etc.) 12 to 15” from the nose. The stimulus is moved from left to right, taking the left eye as far to the corner of the eye as possible and then repeating it again for the right eye. The officer is looking for nystagmus, which is an involuntary jerking of the eyes brought on by (in the officers suspicion) the consumption of alcohol. The test starts with a check for equal tracking (make sure both eyes can see and follow the stimulus) and equal pupil size. The officer will do three different checks for nystagmus: (a) lack of smooth pursuit, (b) sustained and distinct nystagmus at maximum deviation, and (c) onset of nystagmus prior to 45 degree. By using this last test an Officer can allegedly take the number 50 and subtract the angle of onset to come up with a proposed BAC (The Tharps equation). Each check for nystagmus must be done twice for each eye. Some officers will check for Vertical Gazed Nystagmus (VGN), by lifting the stimulus up and down, rather than right to left.

(3) There have been three validation studies: Colorado (1995), Florida (1997), and San Diego (1998).

(4) Colorado: Done in a controlled environment, says that officers made correct arrest decisions 93% of the time when HGN is done in combination with the Walk and Turn (WAT) and One Leg Stand (OLS), with people with a BAC of .10+

Florida: Done on the street. Studies showed officers made correct decision arrest 95% of time, at detecting people with BAC over .10

San Diego: The test was done to determine whether these tests were valid at detecting BAC’s over .08. According to this study, officers made correct arrest decisions 91% of time.
According to studies, officers should be able to classify persons as being impaired by alcohol 77%, just by using HGN. It has not been validated for drugs.

[BLOGGER’S NOTE: A statistical meta analysis by Dr. Steven Rubenzer, PhD in his published peer reviewed study has found that there is a Percent False Positive Rate at 0.10 BAC of .41 (mean value) and also at 0.08 BAC of .28 (mean vakue). The likelihood ratio of only 3.4 (mean value) at BAC of 0.10 and 3.6 (mean value) at BAC of 0.08.]

The Hall of Fame for the www.TheTruthAboutForensicScience.com Forensic Science Geek of the Week:

Week 1: Chuck Ramsay, Esquire

Week 2: Rick McIndoe, PhD

Week 3: Christine Funk, Esquire

Week 4: Stephen Daniels

Week 5: Stephen Daniels

Week 6: Richard Middlebrook, Esquire

Week 7: Christine Funk, Esquire

Week 8: Ron Moore, B.S., J.D.

Week 9: Ron Moore, B.S., J.D.

Week 10: Kelly Case, Esquire and Michael Dye, Esquire

Week 11: Brian Manchester, Esquire