HGN Expert Testimony in North Carolina DWI Trials

Expert testimony, as I described in my previous post on this issue, is admissible under a hybrid rule in North Carolina articulated in Goode, Howerton, and related cases such as Ward. That three-part test is used for most expert testimony and, until 2006, for the Horizontal Gaze Nystagmus test (HGN) used in many DWI prosecutions.

In State v. Helms, 345 NC 578 (1998), the Supreme Court held that the HGN test should be subjected to the same test as in Goode. The state, before offering the evidence in a DWI trial, should show that the foundational requirements of HGN reliability and the officer’s training in the field.

While not an incredibly high burden to meet, that still put the onus on the State to make sure it could show that HGN is actually reliable. There is a lot of peer reviewed scientific literature showing that HGN is not a reliable indicator of impairment. (see Rubenzer) for an overview of scholarly research on HGN.)

But HGN (and DRE) are relatively cost effective ways for the State to try to prove impairment. The HGN “certification” only requires the officer to attend a 24 hour SFST course, which at most costs the State a couple hundred dollars including the NHTSA Student Manual. After that brief course, the officer can go into the field and conduct hundreds of HGN tests on suspected drunk drivers.

Consequently, the Governor’s task force on DWI lobbied the legislature to amend North Carolina’s Rules of Evidence in 2006 to allow the HGN to be admitted into evidence by partially bypassing the test established in Goode and Helms. See also Shea Denning’s article on the School of Government website.

NCRE 702 (a1) reads:

A witness, qualified under subsection (a) of this section and with proper foundation, may give expert testimony solely on the issue of impairment and not on the issue of specific alcohol concentration level relating to the following:

(1) The results of a Horizontal Gaze Nystagmus (HGN) Test when the test is administered by a person who has successfully completed training in HGN.

Anyone who shows they have successfully completed training in HGN can testify. Having completed the training in HGN, I can testify in a DWI trial as an expert. And, believe me, I, like almost all officers, fall far short of an opthamologist’s training.

However, Rule 702 has an initial requirement that the scientific, technical, or other specialized knowledge assist the trier of fact to understand the evidence or determine a fact in issue. If that prong is not satisfied, either because the person’s “expert” testimony is not very learned or deep, or because the person lacked the opportunity to observe HGN because of improper application of the test, then the testimony is not admissible.

This issue is often overlooked by DWI lawyers who assume that because HGN has been declared a forensic science by the legislature and because a person holding a certificate can testify, that there is no way to challenge the admissibility of HGN.

One option available to an attorney challenging the admissibility of the HGN testimony is to take the witness on voir dire where the attorney challenging the admissibility of the testimony can ask questions about how the test was performed and whether the witness has sufficient understanding of HGN to explain to the trier of fact what the presence of HGN means.

Incidentally, even though I tend to think HGN is mostly junk science, officers I respect swear by it. When those officers come to the stand and have a very good understanding of the mechanics of HGN and the underlying science, it makes for interesting testimony and for a good trial where issues can be hashed out.

Drug Recognition Experts – DREs and DWIs in North Carolina – Part II

In my previous post, I gave an overview of what Drug Recognition Experts are supposed to be able to detect. Let’s look at the history of the program.

The program was developed in 1979 in the Los Angeles Police Department by two sergeants, Dick Studdard, a traffic officer, and Len Leeds, a narcotics officer. According to the student manual, they undertook independent research by consulting with physicians, enrolling in relevant courses, studying textbooks and technical articles in order to identify a quick an easy way for officers to identify the drugs (other than alcohol) that may cause impairment in drivers.

Unfortunately, no actual experts were consulted in the actual construction of the program and the program has very little scientific rigor (more about that later).

The program received official recognition by the LAPD in 1979, and in the 1980s NHTSA, the National Highway Traffic Safety Administration, and the International Association of Chiefs of Police became involved.

NHTSA is the primary funding agency behind the DRE, also known as the DEC program. IACP, based in Alexandria, Virginia, is the organization that actual administers the program.

The student handbook on DREs claims that “[p]roof of the effectiveness of the DEC program began to be accumulated from the very outset of the program.” But that proof is circular – arrests and convictions are used to claim proof that impairment was proven, when in fact arrests and convictions were probably the consequence of other factors and not an accurate detection of impairment by DREs.

No peer-reviewed studies have ever been conducted in support of the DRE program. And few scientists have ever found the program to be effective. Support for the program has been mostly generated by the IACP and NHTSA, without regard to its scientific reliability, as we’ll explain in future posts.

Drug Recognition Experts – DREs and DWIs in North Carolina – Part I

If you’re arrested for a DWI in North Carolina, the State needs to prove that you were impaired by an impairing substance. Driving while impaired by a medical condition is not, in and of itself, illegal. But driving while impaired by an impairing substance is a violation of NCGS 20-138.1 or related implied consent offenses.

Proving a DWI is far simpler in North Carolina if the impairing substance is alcohol. The state may conduct a breath test or a blood test and produce a BAC or BrAC of .08 or above. This is offered to prove a defendant’s guilt. And while that is not always accurate – the Intox EC/IR II machines combine two technologies – fuel cells and Infrared technologies – which have been known to be flawed for decades – North Carolina’s General Assembly has, through a combination of laws, made it difficult for defense lawyers to attack the validity of the blow.

Proving a DWI that is a result of suspected drug use (either legally prescribed or illegally consumed) is usually more complicated for the State to prove, unless the drug is a Schedule I. If the drug is a schedule I, the State merely has to prove the existence of any amount of metabolites within the blood if the blood was taken at a relevant time after the driving such at the Schedule I substance was consumed before or during the driving.

Providing DWI that is the result of non-Schedule I suspected drug use is the most difficult for the State to prove. Medical professionals fully understand that evidence of drugs in blood is merely shows that, at some point in the past, the person consumed the drug. Medical professionals cannot pinpoint when the drug was consumed.

That’s where the Drug Recognition Expert (someone who is trained in the Drug Evaluation and Classification Program) comes in.

A DRE is a specially trained law enforcement officer – only the best and the brightest are sent to DRE courses – who, it is claimed, can identify:

  1. Whether someone is impaired
  2. Whether that impairment is from a physical defect or from drug consumption
  3. And the classification or identification of the particular drug.

Most states require that DREs be admitted as experts by showing in court that the officer is trained as a DRE and that DRE is a generally accepted field within in relevant the scientific community.

As we’ll explore in greater depth in future posts, Drug Recognition or DEC are not accepted within the relevant scientific community. Opthamalogists, toxicologists, and medical doctors are either unaware, or dismissive of DRE. No leading researcher or expert actually regards DRE as anything other than junk.

DRE is widely regarded within the scientific community as a joke.

Unfortunately, in North Carolina, Rule 702 codifies DRE as an accepted forensic science. That’s because the North Carolina General Assembly has chosen to embrace junk science.

Fingerprint Analysis is Unreliable

Most people get their understanding of forensic science from crime shows, such as CSI, or movies.

The impression that’s given is that forensic science is incredibly accurate and reliable. For instance, most people believe that fingerprinting analysis is a reliable way to determine whether someone touched an item. Or they believe that shoe print analysis can help determine whether someone walked in a particular place.

Such beliefs are fine in a crime drama, where no real lives are at stake.

But in a criminal case – in a courtroom – the belief that fingerprints and shoe prints are reliable forensic tools can be catastrophic.

One of the reasons why such analysis is allowed into a courtroom is that judges are usually ill-equipped to determine whether a particular forensic science is reliable. So they defer to the people trained in that science.

And those people suffer from a separate problem. Having spent weeks, months, or years as a fingerprint analyst, a fingerprint analyst is unlikely to say that his field is unreliable.

Consequently, the very people who testify in a courtroom for the prosecution (and even people testifying for the defense) are same people who will say that their testimony is reliable. It’s a circular pattern that, unfortunately, permits juries – who usually know very little about these subjects – to hear about what is essentially unproven forensic science.

Take fingerprint analysis, which until the advent of DNA, was a major way (in addition to serology/blood typing) that investigators linked a defendant to a crime scene.

The National Academy of Sciences issued a report in 2009 pointing out that the evidence to support the reliability of many techniques, including most kinds of fingerprint analysis, is lacking.

As a result, there has been little rigorous research to investigate how accurately and reliably many forensic science disciplines can do what they purport to be able to do. In terms of a scientific basis, the disciplines based on biological or chemical analysis, such as toxicology and fiber analysis, generally hold an edge over fields based on subjective interpretation by experts, such as fingerprint and toolmark analysis. And there are variations within the latter group; for example, there is more available research and protocols for fingerprint analysis than for bitemarks.

adding that:

In addition to investigating the limits of the techniques themselves, studies should also examine sources and rates of human error, the report says. As part of this effort, more research should be done on “contextual bias,” which occurs when the results of forensic analysis are influenced by an examiner’s knowledge about the suspect’s background or an investigator’s knowledge of a case. One study found that fingerprint examiners did not always agree even with their own past conclusions when the same evidence was presented in a different context.

So the next time you hear about fingerprint analysis, be very skeptical about whether the analysis shows what it purports to show.

One Side of a Story

One of the unending frustrations of a criminal lawyer is watching his clients’ reputations being smeared in the media, among the clients’ friends or family, and with the clients’ employer.

Unfortunately in our society, when someone is arrested, charged, or indicted, people assume there must be some reason for the charge. This is a natural reaction, but unfortunate, especially given how easy it is to arrest, charge, and indict someone.

An arrest is based on probable cause, which basically amounts to an opinion by the charging officer based on some specific facts that the person had or was in the process of committing a crime. The problem is that the specific facts are in many cases innocent, and only interpreted as suspicious by a police officer trained to arrest people.

Let’s take a simple example from DWI law. Let’s say a person was driving slowly, and at some point his car started straddling two lanes for 300 feet, causing the officer to pull the car over. Let’s assume upon pulling the car over, the officer approaches and smells a “strong odor” of alcohol coming from the car. Let’s then assume that the officer then asks the person to step out of the car and asks the person whether he’s been drinking tonight. Let’s assume that the person admits that he has had four beers.

Let’s further assume that this interview occurs on the side of a major street (where there is moderate to light traffic) at 2:00 am in the morning in the middle of winter.

Let’s assume that this person has never been in trouble with the law before. Let’s assume that this person then is asked to perform some field sobriety tests. The person is very polite and cooperative, and wants to do everything he can to help the officer out. But the person has trouble keeping his head still during the eye exam – called the Horizontal Gaze Nystagmus test (HGN). Given that the person failed to keep his head still, the officer marks down on his report that person “failed to comply.” (More about that later!)

Let’s then assume that the person is asked to do the Walk and Turn test (WAT), the second in the battery of Standardized Field Sobriety Tests. The officer instructs the person to take nine steps heel to toe on an imaginary line, execute a turn, all while keeping his arms by his side, and then return nine steps. The person performs this test, but, according to the officer, fails to make contact heel-to-toe (even though contact is not required according to NHTSA in order to perform well on that aspect of the test). Let’s assume that the person, trying to follow the officer’s commands, takes his time and keeps his arms by his side. The officer writes in his report that the person “took abnormally long” to complete the test and kept his hands “glued bizarrely” to his side.

Next the officer asks the person to complete the One Legged Stand (OLS) test, the third in the battery of three SFST tests. The person has trouble keeping his balance for more than 6 seconds, let alone the 30 required by the test. The officer fails to note that the ground on the side of the road had loose rocks.

On the basis of those three test, the officer charges the person with a DWI.

The person’s performance on those tests – as described by the officer – and his answers to the questions look pretty bad.

And that’s why it’s important to have competent, aggressive defense lawyers. Because, seen another way, the driver’s performance was completely normal and not indicative of impairment.

For instance, the person was driving slowly, but that’s because the person was from out-of-town. The person did have four beers, but over a seven hour period (that’s about a drink every two hours). The odor was strong, but that’s because there were three other drunk people in the car when the officer stuck his head down to the driver’s side window.

The driver had trouble keeping his car in his lane for about 300 feet (incidentally, that’s only 1/20th of a mile, not very long at all) because the driver was changing the radio station.

The driver did have trouble keeping his head still during the eye test, because the officer was telling him to follow a pen with his eyes and the person’s contacts were extremely dry. The person’s eyes were bloodshot, he’d gotten up for work at about 8 the previous morning, and had been up for about 14 hours by the point he was stopped on the side of the road.

And so on.

There are two sides to every story. Before you judge someone for having been arrested, stop to consider what you haven’t heard.

SFSTs are part of North Carolina Basic Law Enforcement Training

In the late 1970s and early 1980s, the National Highway Traffic Safety Administration (NHTSA) evaluated a variety of field sobriety tests to determine which ones were scientifically accurate. NHTSA identified the Southern California Research Institute as the center to conduct a thorough testing of the various field sobriety tests to determine which ones had the highest level of accuracy.

The SCRI and NHTSA determined that three tests had the highest level of accuracy: the Horizontal Gaze Nystagmus (HGN) test, the Walk and Turn Test (WAT), and the One Legged Stand (OLS) test. These three tests became the Standardized Field Sobriety Tests. While officers can perform other kinds of tests at the roadside, none of those other tests are part of the SFSTs and none of those tests have been evaluated for their validity and reliability.

One common non-SFST test is an ABC test. The officer will ask the person to say his or her ABCs from a letter to another letter. The problem with the ABC test is that no one knows whether it’s indicating impairment, or whether it’s simply indicating that, in stressful situations, people simply don’t do their ABCs very well regardless of whether they are impaired.

In 1986, the International Association of Chiefs of Police recommended that member law enforcement agencies begin using the Standardized Field Sobriety Tests developed by NHTSA as part of their investigations into Driving While Impaired (DWI, DUI, OUI) incidents.

One of the important things to know about the Standardized Field Sobriety Tests is that they must be conducted in accordance with NHTSA instructions in order to maintain their validity. The NHTSA SFST student manual states in all capital letters that “IF ANY ONE OF THE STANDARDIZED FIELD SOBRIETY TEST ELEMENTS IS CHANGED, THE VALIDITY IS COMPROMISED.”

Sometimes when a defense attorney shows that the SFSTs have not been performed according to NHTSA guidelines, a judge will dismiss that argument by saying “Well, NHTSA is not the Law in North Carolina.”

This is only partially true. It’s accurate that North Carolina has not formally adopted NHTSA guidelines as the “law”.

But North Carolina’s Assembly has in NCGS Sec. 17C created the North Carolina Criminal Justice Education and Training Standards Commission.

The Commission has the sole authority to set the minimum training standards in order to be recognized as a law enforcement officer by the State of North Carolina.

The Commission has established Basic Law Enforcement Training (BLET) as the formal minimal training standards that all people must complete before they can assume the duties of a Law Enforcement Officer in North Carolina.

And, the BLET training manual establishes the Standardized Field Sobriety Tests as validated by NHTSA as the tests Law Enforcement Officers are permitted to use in order to determine whether someone has been DWI (Driving While Impaired).

So, in an important sense, NHTSA is North Carolina law.

Raleigh DWI Lawyer: Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus test – also known as the eye test or finger test – is considered the most reliable of the Standardized Field Sobriety Tests conducted on the roadside to determine whether a driver is impaired. If you’ve been stopped for a DWI in North Carolina, call [#phone#].

The HGN is not a sight test. It does not measure how well you can see. It merely measures whether there are involuntary movements or twitching (nystagmus) in the eye as it moves from left to right and up and down. These two types of nystagmus – horizontal and vertical – occur for a variety of reasons. One of the reasons they occur is because the person is impaired.

The problem with the HGN test is that first it is many times not administered properly. If the person is tested in front of flashing police lights, or if the person is tested while seated in their car with their head twisted, the results will not be accurate.

In addition, nystagmus can be caused by different medical conditions that are unrelated to whether the person has been drinking. For instance, if the person has suffered from head trauma in the past, or has consumed significant quantities of caffeine, the person may show nystagmus (or twitching) without actually being impaired.

For this reason, while HGN is considered a very reliable SFST, it can be more easily shown to be faulty in court under the right questioning by a Raleigh criminal lawyer.

Don’t Perform Standardized Field Sobriety Tests

Too often people who encounter the police don’t understand that they have a right to remain silent. Police do not need to inform a person of these rights, unless police place the person into custody and wish to interrogate that person once in custody. Call a Raleigh Criminal Lawyer at [#phone#] if you need someone who can defend your rights in a criminal matter.

A DWI or DUI or Drunk Driving stop is a very common interaction with police where people fail to exercise their rights.

Let’s take a common scenario:

1. Sometimes police will spot a car swerving or running lights or otherwise appearing to be driven by someone who is drunk or impaired. Other times police will patrol areas around bars, clubs, or universities. Raleigh police, for instance, know that North Carolina State University (NCSU) students like to go to certain bars, or clubs in the Warehouse District. So naturally they will patrol those areas.

When police spot a car that is either being driven improperly, or that they see coming out of a parking lot of a bar or restaurant late at night, they suspect, with good reason, that the person may be drunk.

However, mere suspicion – a hunch – is not enough for police to arrest that person. Police need more information in order to make a legal arrest.

2. Once police have stopped the car – and let’s assume that they have stopped the car for a valid, and legal reason – the police simply can’t arrest the person on suspicion of drunk driving unless they observe additional clues.

This is the most important part of the driver’s encounter with police. At this point, a lot is riding on what the driver does.

Perhaps the driver, when asked by the police officer whether he has been drinking, says “Yes, sir. But I only had two beers.” That may be enough for the police officer to arrest the driver, especially if the police officer has seen the person driving in an erratic or reckless fashion.

If the officer asks the driver to step out of the car, and the driver complies and performs standardized field sobriety tests (SFST) or other tests administered by the officer, that is simply giving the officer more information so that the officer can prove the driver has been driving while impaired. Because the SFSTs are designed to detect impairment, they are very unforgiving, which means that even if you were perfectly sober, you might fail the SFSTs.

But let’s consider how a driver can avoid arrest. What if the driver simply says: “Officer, I respect your job, but I won’t answer any questions without a lawyer.” At that point, the driver is not giving the officer any additional information. If the officer says, “Would you please step out of the car?” the driver can then respond: “Am I under arrest?”

If the officer tells the driver he is under arrest, then the driver must step out of the car. But because the officer was unable to collect any additional information about the driver before the arrest, the legality of the arrest will stand or fall on whatever the officer observed pre-arrest.

In other words, the driver has very much improved his chances of winning a DWI case.

A driver should always politely, but firmly refuse to perform any field sobriety tests or answer any questions.

A driver may wish to politely but firmly refuse a chemical analysis test performed post-arrest at the jail or police station, understanding that the refusal to perform that chemical analysis (breath test) will probably mean an automatic suspension of the person’s license for a year.

The important thing to remember is to always be polite, but always refuse to answer questions without a lawyer present.

SBI Abuses Impact Criminal Trials

Recent revelations that the analysts at the North Carolina State Bureau of Investigations misreported results, lied about lab tests, failed to report results that were inconsistent with what prosecutors wanted to hear has created shock waves in North Carolina.

The News and Observer reports that distrust is building in courtrooms throughout the state:

“All this information came from the SBI, and we all know what they say doesn’t matter anymore. They have no credibility now,” [Criminal Defense lawyer] Reece said in an interview Monday.

It is a scene expected to play out in courtrooms across the state in the coming months as attacks on the SBI’s credibility reverberate. Judges anticipate a slew of motions from prisoners seeking a review of their cases, citing problems over SBI analysis. Prosecutors are trying to figure out how to defend SBI agents and analysts, often their star witnesses in front of juries.

Shoddy work at the SBI

The Raleigh News & Observer is running a series this week on the North Carolina State Bureau of Investigation (SBI). This is the agency in NC chiefly responsible for providing scientific support to local law enforcement agencies. The SBI conducts blood analysis, blood spatter analysis, fingerprint analysis and other kinds of scientific tests.

The problem is, as the N&O has observe, at least some of that work has been shoddy, and the chief blood pattern expert has, according to the News and Observer, conducted unscientific tests to support prosecution theories.

Deaver is a major character in the emerging story of the SBI’s troubles. His withholding of evidence contributed to three judges in February declaring Greg Taylor innocent of a 1991 murder and freeing him from life in prison. Attorney General Roy Cooper then ordered an audit of the blood analysis unit.

At the bureau’s crime labs, where Deaver has been a key agent and trainer, analysts charged with using science to solve crimes have hidden test results or concocted bizarre experiments to shore up a prosecutor’s case, a News and Observer investigation reveals.



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