|
The scientific determination of alcohol intoxication is always an
estimate regardless if the expert is an ordinary police officer armed
with a breathalyzer or a forensic toxicologist armed with the most
sophisticated laboratory equipment. This is because over 90 million
Americans who drink have different body chemistries and physical
constitutions that exhibit extraordinary variation in the behavioral
effects of alcohol our society has decided to criminalize as
"intoxication". The crime of "drunkenness" has
been the most common misdemeanor since colonial times. It's hard not
to admit a class or moral bias against intoxication, and it may very
well be the perfect example of how the law reaffirms moral boundaries.
See Criminal Law lecture #13 (optional reading) if you're interested
in legal distinctions between the act and status of intoxication as
public indecency.
It's also no secret that about 17,500 automobile deaths a year (about
40% of all traffic deaths) and over 2,000,000 automobile injuries are
alcohol-related. Alcohol abuse, despite signs of decline, is still at
epidemic proportions. That's why the law doesn't require full-fledged
forensic toxicologists for routine, ordinary alcohol intoxication
testing. Those people's services are better put to use on attempted
overdose cases or whether children were exposed to lead paint, for
example. Instead, judges have been taking the word of police officers
for decades, and the law is replete with numerous examples of
precedent where police officer testimony carries the same weight as
expert testimony, or at least testimony of the "skilled
witness" type.
THE
HISTORY AND DEVELOPMENT OF INTOXICATION TESTING
In 1938, Dr. R.N. Harger developed the first testing instrument,
called the Drunkometer, which was followed in 1941 by the Intoximeter,
developed by Glenn Forester, and the Alcometer, developed by Prof.
Leon Greenberg. All of these machines were designed to take a deep air
sample (breath from the alveolar sacs, the site of gas exchange in the
lungs) and calculate the rate or proportion of alcohol-in-blood to
alcohol-in-breath. This proportion is known as the partition rate, and
since 1938, it has been generally accepted that the ratio is
approximately 1 to 2,100. All breath testing instruments since then
have this ratio built into their circuitry, and sometime during the
1950s, the estimated alcohol-in-blood using this proportion became
referred to as BAC (blood alcohol concentration, the percent weight by
volume, or % w/v, based upon grams of alcohol per cubic centimeter of
blood or 210 liters of breath).
NHTSA (the National Highway Traffic Safety Administration) and LEAA's
National Highway Administration played a key role during the 1970s and
80s in encouraging the proper training of police officers so that they
would have sufficient foundation to admit HGN (horizontal gaze
nystagmus) testing and other field sobriety tests such as
finger-to-nose, walk-and-turn, or the one-leg stand. In spite of
opposition by ophthalmologists and other medical people (at least 60
different physical conditions cause nystagmus), NHTSA and the police
community managed to convince most judges, prosecutors, and lawmakers
that these techniques were reliable, and in some states became the
equivalent of "non-scientific" Frye-approved techniques.
Field sobriety testing is now part of every basic policy academy
curriculum (at least eight hours of training is required in most
states). Perhaps it might be instructive to examine this "skilled
witness" standard in some detail; State v. Superior Court 149
Ariz. 269 (1986):
HGN and other field sobriety tests need not be held on the basis of
the Frye principle of "general acceptance" since when
administered by a trained police officer are sufficiently reliable to
corroborate and establish, but not to quantify, probable cause. The
police witness, though not necessarily college trained, will
nevertheless be considered an expert in a non-scientific category for
which no expert testimony is required.
The story of nystagmus testing is a story about the dispensing of true
scientific evidence and a devaluation of whatever meaning the word
"expert" has. Little support for its reliability can be
found outside of police training manuals (for example: any eye doctor
will tell you that wearing contact lenses makes a difference but
police manuals say it makes no difference at all), AND this may sound
like a harsh criticism, but it's the one area of police science where
the less college education one has, the more steadfast and credible
the "skilled witness" will be in advocating its reliability
(at least in knowing what 45 degrees or an eye jerk looks like).
Judges tend to blindly accept these tests, and some prosecutors have
attempted to use HGN as direct evidence instead of probable cause.
Roadside testing (other than HGN) does not require probable cause, and
it may make sense to refer to two (2) categories of tests: 3 STEPS OF
HGN TESTING:
1. Eye
jerks following an object moved laterally
2. Eye
jerks trying to use peripheral vision
3.
Point at which jerking first occurs estimates BAC: 40 degrees equals
.10; 35 degrees equals .15; 30 degrees is .20+
Tests that require the suspect to do something (so-called evidentiary
tests), including blow into a tube, give blood, stand on one leg, walk
a line, touch their nose, HGN. The issue is whether these sufficiently
reliable techniques constitute a search or a frisk, and most states
have gotten around this with implied consent laws that trigger
something akin to a search incidental to arrest.
Test that don't require the suspect to do anything (so-called
preliminary tests), including erratic driving, staggering, slurring,
having bloodshot eyes, the odors associated with alcohol. The issue is
whether these roadside techniques or checkpoints constitute an
invasion of privacy, are searches under plain view, and are the basis
of probable cause or just reasonable suspicion. (Discussion question:
Write a checklist of things you would recommend looking for, in
addition to those mentioned above, that would constitute a "DUI
offender profile".)
Sometime around 1984, Smith & Wesson sold off its Breathalyzer
Division, and although such devices were around prior to that date,
this is the year of the first truly automatic machine that found its
way into most police departments -- the Breathalyzer Model 1000. NHTSA,
DOT (the Department of Transportation), and the National Safety
Council all contributed to the popularity of these
("DOT-approved") devices and the market-mania that
accompanies today's debates over whether the Intoxilyzer 5000 is
better than the Breathalyzer 7410, other various Intoximeters/Intoxilyzers
or portable handheld devices. Mobile units tend to be used at
checkpoints or in school demonstrations.
BLOOD
TESTS
The
best medico-legal scientific method for determining anything close to
"impaired judgment" is an estimate of the amount of alcohol
that has flowed through the blood vessels of the brain. Theoretically,
a blood sample drawn from the brain's blood vessels (or from spinal
fluid) would yield the most accurate results. However, for practical
purposes, blood samples are usually drawn from the arm, and there is
little or no research on circulatory systems regarding whether arms
are the best place to estimate brain alcohol concentration (some
people may have poor circulation in one or more extremities).
With
blood tests, the law allows a suspect to have an analysis done at a
laboratory of their own choice. Two samples are therefore drawn at the
same time (as close to the traffic stop as possible), one vial for the
police and another vial for the suspect's hospital. A preservative
(sodium fluoride or mercuric chloride) must be added to the vials,
otherwise putrefaction begins in a matter of hours. The vials must
also not be exposed to sunlight or heat.
The
most commonly used laboratory test for alcohol in a blood sample is
called the dichromate oxidation method (a type of chemical test). This
involves using ready-made ampoules consisting of a mix of chromium
dichromate and sulfuric acid. If anything containing alcohol is
introduced into this solution, a residue of chromic sulfate will form
due to oxidation. The unconsumed amount of dichromate or the chromic
sulfate formed is then measured which gives the percentage of alcohol
in the sample expressed in percent weight per volume, which is exactly
the same formula for estimating BAC.
Many
states require a blood test in all traffic fatality incidents, and
with most commercial drivers (who are held to be intoxicated at a much
lower, .04%, standard). Congress also (under the Uniform Vehicle Code)
withholds federal highway funds from any state that does not use
intoxication standards of .10% or .08% for all drivers. At the state
level, these standards translate into what are called "per
se" laws, making it illegal per se to be in physical control of a
vehicle while having an alcohol concentration above .08%. The UVC
presumes any concentration of .08% or more is "under the
influence", anything .05% or less is "not under the
influence", and anything between .05% and .08% shall not give
rise to any presumptions, but can be considered with other competent
evidence in a police determination of "under the influence"
or not. A "per se" law gives a jury no choice but to
consider the defendant intoxicated.
As with
all intoxication testing, if the technique, method, or instrument used
produces a digital display and a printout, the witness testifying for
the prosecution need not be a chemist or scientist. Occasionally, the
"professional quality" of a laboratory comes into question
and/or the chain of evidence, but typically, it's the police officer
or someone else who talked to the defendant that testifies as an
expert in what is called retrograde extrapolation. The expert states
that they know when the drinking started and ended, the absorptive
interval of time, and when the person last ate (one reason why police
ask these questions early on in DUI stops). This witness then
extrapolates backward in time from the BAC estimation to the time of
driving, accounting for the full ingestion and absorption of alcohol,
and is questioned as to whether it is scientifically impossible (with
reasonably certainty) for the person to be below the legal limit at
the time of the offense. The prosecution is never required to produce
such a witness; the mere mention that they can is often admissible and
persuasive in many cases. Some states do not allow the defense any
opportunity to present their own extrapolation evidence. (Discussion
question: Defend the seemingly one-sided and unfair practice of
retrograde extrapolation from a prosecutorial viewpoint, then argue
against it from a defense viewpoint. Devote equal time to each side.)
URINE
TESTS
Urine
normally contains about 1.3 times as much alcohol as blood, but
attempts to relate this to BAC depend on a number of bladder
conditions. If alcohol is consumed with a full bladder (the person has
not voided themselves), the test would produce a false negative
(inaccurately underestimate). If the person consumed alcohol with an
empty bladder and had not voided, the test would produce a false
positive (inaccurately overestimate). Urinalysis tests, most of the
time, are not favorable to the defendant. Higher concentrations of
alcohol in urine will occur over a longer period of time than in
blood.
Law
enforcement practice is to take two (2) samples, at 30-minute
intervals, preferably the latter sample after the bladder has been
emptied. Again, precautions must be made to add preservative and keep
the samples from exposure to light and heat. Urinalysis requires a bit
more sophisticated laboratory equipment than for blood testing. One of
three (3) laboratory methods are used: (1) chemical tests; (2)
biochemical tests; and (3) gas chromatography. Gas chromatography is
the most widely used because it can distinguish alcohol from ketones
and aldehydes (a problem that exists with diabetics and people with
other disorders that blood tests are not capable of controlling for).
While chromatography produces a printout and lends itself to
quantitative analysis, it always requires the expert testimony of a
scientist to be admissible in court. This is because chromatography
results are subject to both quantitative and qualitative
interpretation.
A NOTE
ON LABORATORY QUALITY
It's
important that police departments choose professional, high-quality
vendors to get their supplies (ampoules, vials, preservatives,
chemicals) from. At a minimum, there should be lot numbers on each and
every product which indicates manufacturer testing and quality control
procedures.
It's
also important that packaging and preservation of evidence be
consistent. The FBI has taken the lead in proposing standards (paper
or plastic), but some laboratories have their own preferences, and
police departments often run out of certain supplies and make do with
what's on hand (which should be avoided). Bottled specimens sent to
any lab should also have expiration dates on them, following whatever
guidelines are listed on the preservative's brochure. There should
also be independent corroboration (a statement by witnesses) of the
sample being collected, packaged, and mailed out (chain of evidence).
Laboratories
themselves, in order to be considered "professional", must
adhere to rigorous internal and external controls. Externally, they
should be site visited or audited by outsiders on a regular basis as
part of a certification or accreditation process. Internally, they
should have excellent record-keeping and quality controls. It must be
assured that all chemical reagents are fresh as things like
dichromates and permanganates tend to have short shelf life.
Instruments must be calibrated and standardized (using equilibrator
solutions) after every use. Instruments, syringes, vials, and flasks
used in alcohol testing should never be cleaned or sterilized in
alcohol solutions. Boiling, likewise, will often trap alcohol-related
impurities or distillates into the equipment. Containers must not be
contaminated with foreign substances, and this includes the air.
Exposure to air not only contributes to putrefaction of alcohol
samples but transmits oxidizable organic materials that may produce
false positives.
BREATH
TESTS
Breath
tests are an indirect yet most practical way of estimating alcohol
intoxication. They have the advantages of being able to produce
digital display and printed readout (calculated in terms of BAC per
the built-in 1 to 2,100 ratio), results obtainable in minutes (as
opposed to long waits for laboratory reports), a short chain of
evidence (custody), low operator skill requirements, low cost, and
little invasiveness of the human body. They have the disadvantages of
breath samples being difficult to preserve (silica gel is about the
only thing), relying upon cooperation of the suspect, requiring a
waiting period of 15-20 minutes (to eliminate residue mouth alcohol),
interference from foreign sources (RFI or radio frequency
interference), and interference by other objects/odors in mouth.
Police have no constitutional duty to preserve breath samples (under
Brady rules), and there's usually no requirement for a second test
sample (as with blood or urine, although some departments do perform a
second test).
Police
officers are the experts when it comes to breath testing. They
typically attend a breath testing school, and are taught only that
which the designers of the instrument feel it is necessary for the
officer to know and which they feel he/she can understand and relate
to others. A lot is left out, and if a defense attorney tries asking
probing questions about the digestive tract and respiratory systems,
they will quickly be perceived as trying to discredit an honest,
hard-working officer with irrelevant scientific nonsense. "I'm an
operator, not a scientist" is the usual response from a
non-scientific expert.
Nevertheless,
most states have constructed elaborate certification systems which are
a sought-after training by police officers. Becoming certified in
breath testing offers some degree of protection from challenges to
professionalism. The following is an example from the system in North
Carolina:
Approximately
5,000 law enforcement officers in North Carolina have been trained and
certified as Chemical Analysts on the Intoxilyzer 5000 breath alcohol
testing instrument. Each year about 1,000 officers are certified for
the first time. The initial training on the Intoxilyzer is a one-week
school in which law enforcement officers receive training on law,
rules and regulations, theory, science of alcohol and the human body,
and hands-on use with the Intoxilyzer. Chemical Analysts are required
to attend a one-day recertification class every two years in order to
maintain their permits. Approximately 2,000 Chemical Analysts are
recertified annually. A training class is also provided on portable
breath alcohol test devices. Approximately 2,500 officers complete
that training each year. In addition to providing Law Enforcement
Training, Forensic Tests for Alcohol's 14 field staff members are
responsible for maintaining the 252 Intoxilyzer 5000 breath test units
located in 162 law enforcement test sites throughout the state.
There
are actually three (3) different types of breath testing instruments:
(1) desktop models, such as the Intoxilyzer 5000, the kind we've been
discussing, although modern infrared devices are also becoming common;
(2) PBTs, or Preliminary Breath Testing devices; and (3) PASDs, or
Passive Alcohol Screening Devices.
PBTs
(like the ALERT models or Intoximeters) are sometimes referred to as
handheld "roadside" devices or "portables", and
are about the size of a pocket calculator. They require a person to
blow into a balloon or a plastic tube about the size of a cigarette.
Most PBTs are calibrated to give a "pass-fail" reading, set
at .05% (for no presumption but the collection of other corroborative
evidence) or .08% (for a presumption of intoxication). A few models
give a digital readout of the estimated BAC. These devices are
intended to be used for preliminary purposes only, as screening
devices along with an officer's other observations. They are not
normally admissible in court on the factual issue of intoxication, but
they are active devices, requiring the suspect to do something, hence
they are likely to be considered as legitimate search evidence under
plain view, incident to arrest, or some other doctrine.
PASDs
(like England's Lion Alcometer), by contrast, are portable passive
devices that sniff or sample the air around a person. They are about
the size of a flashlight, consisting of a miniature fan (to pull the
air in), a salt-based alcohol sensing device, a sensitivity knob, and
an indicator light. A PASD is held in front of a person's face (for as
long as it takes to exhale) or in the head area of the driver's
compartment (once they have left the vehicle). The latter technique is
inappropriate when there are open bottles of alcohol in the vehicle
and/or drinking passengers. Passive devices often give false positives
in the presence of car exhaust, perfume, aftershave, hair oil, and
airborne contaminants. By adjusting the sensitivity knob for such
considerations, passive devices often give false negatives (anything
less than maximum sensitivity works in the favor of the suspect).
PASDs work best in temperate climates (those consistently around 70
degrees), and tend to be less sensitive in cold weather and more
sensitive in warm weather. Like PBTs, PASDs are not designed to be
admissible in court as a substitute for BAC readouts. However, they
effectively counter the challenge of a suspect who says they haven't
been drinking.
SOURCES
OF ERROR WITH INTOXICATION TESTS
As with
most machines, error is classifiable into operator and equipment
failure. However, alcohol intoxication theory may be more
fundamentally flawed. The 1:2,000 partition ratio (which has been
assumed true since 1938) and is an integral part of the internal
calibration of all machines may NOT be reliable. There's scientific
research that the true ratio varies from 1:1000 to 1:3000, depending
upon the individual. Just to name a few differences: females absorb,
distribute, and eliminate alcohol 10% faster than males; heavy people
have different tolerances in their stomach linings; and physically fit
people have different tolerances in their lung sacs. Some judges are
aware of this, and exercise a little leniency, or give-and-take, when
the estimated BAC is a close call. For example, if the state's
standard is .08%, a court might permit and closely consider challenges
for police estimations in the .09% or .10% range. However, it's pretty
much hopeless to raise a defense challenge in a case where the BAC is
.12%, .13%, or higher.
There's
also controversy surrounding the conventional wisdom of charts that
imply a connection or nexus between certain BAC ranges and certain
behaviors. Aside from the seriousness of the matter, almost everyone
has heard the joke that "you should be in a coma" with that
much alcohol. Various other charts or popular "drunk wheels"
showing how to calculate BAC based on amount and body weight are a
step in the right direction, but are likewise controversial. As
previously mentioned, there are at least 60 different pathologies
other than alcohol intoxication (even personality disorders) which
produce similar behavioral symptoms. It's generally accepted that
alcohol affects higher cerebral functions (like judgment and
self-restraint), but only at higher levels is there anything like
problems with nerve impulses or muscular control. (Discussion: Has
society set the standard for alcohol-related impairment too low or too
high? Defend your answer by relating your choice of a specific BAC
range to possible social harms.) Here's a typical BAC range chart:
0.03 -
0.12 Euphoria Euphoria, sociability, talkitiveness Self-confidence,
decreased inhibition Diminuation of attention, judgment and control
Beginning of sensory-motor impairment Loss of efficiency in finer
performance tests 0.09 - 0.25 Excitement Emotional instability, loss
of critical judgment Impaired perception, memory, comprehension
Decreased sensatory response, reaction time Reduced visual acuity,
peripheral vision Sensory-motor incoordination, impaired balance
Drowsiness 0.18 - 0.30 Confusion Disorientation, confusion, dizziness
Exaggerated emotional states Disturbances of vision and/or perception
Increased pain threshold Staggering and slurred speech Apathy,
lethargy 0.25 - 0.40 Stupor Inertia, approaching loss of motor
functions Lack of response to stimuli Inability to stand or walk
Vomiting, incontinence Impaired consciousness, sleep or stupor 0.35 -
0.50 Coma Complete unconsciousness Depressed or abolished reflexes
Subnormal body temperature Incontinence Impairment of circulation and
respiration Possible death 0.45 + Death Death from respiratory arrest
Some
defense attorneys claim there are at least 30 different ways to
"beat" a DUI rap, even more for opinion evidence of the
field sobriety nature. The following is a short list of the most
commonly seen DUI defenses:
1.
Operator Error - in general, not following the operator's manual,
which is sometimes countered by a good faith argument, but specific
errors, like not following the 20-minute rule, cannot be overlooked.
2.
Improperly Dedicated Power Source - the power circuit should be
grounded and surge-protected. Also, there should be no cameras,
microwaves, coffee pots, toaster ovens, or other electrical appliances
that can cause "spikes" on the same circuit or even in the
same room. Sometimes, defense attorneys will take a picture of the
police room.
3.
Radio Frequency Interference - RFI occurs when a component of the
machine acts as an antenna. Also, no cellular or cordless phones
should be used in the area at the time. However, testing device
manufacturers have made great strides in producing equipment nowadays
that locks out, checks, or otherwise controls for RFI.
4.
Mouth Contamination - some of the things that cause early
"spikes" in the readout are menthol tobacco (smokeless),
mints, lozenges, denture adhesive, lip balm, breath spray, recent
dental work, asthma inhalers, and pepper spray. If readouts are
"spiking", a flatline or plateau in the readout indicates
the desired alveolar air.
5.
Environmental Contamination - some of the things in the air that cause
"spikes" include solvents in the workplace (Brasso), hair
spray, nail polish, and airplane glue.
6.
Physical Condition of Suspect - a variety of things affect accurate
readout, including:
Hyperventilation
- being upset, crying, vomiting, for example
Sitting
down and bending forward - this pushes air up from the stomach
Gastric
reflux - if the suspect has gas or indigestion
Diabetes
- if the suspect's sugar levels are off
Liver
malfunction or disease - as well as renal dysfunction
Tuberculosis
- TB can get trapped permanently in the machine
Prescription
drugs - Nyquil, Sinus medication, Antabuse, many others
Diet -
if the suspect has been fasting or is on a high-protein regimen
Body
temperature - if because of illness or menstruation. The general rule
is that a one degree elevation in body temperature equals an increase
of .03% in BAC.
|
