Session 2 – Detection and General Deterrence Standardized Field Sobriety Test Course Keys to success:

Session 2 – Detection and General Deterrence

Standardized Field Sobriety Test Course

Keys to success:

• Officers skilled at DWI detection

• Willing to arrest all violators detected

• Policies and application supported by

agency

In each state where the number of DWI

arrests increased, alcohol related crash

fatalities decreased

Improve DWI Detection

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Improved DWI detection can be achieved in virtually every jurisdiction in the country.

The keys to success are police officers who are:

• Skilled at DWI detection

• Willing to arrest every DWI violator who is detected

• Supported by their agencies in all aspects of this program, from policy through

practical application.

Since the historical Stockton study numerous states have conducted similar studies to

determine the degree of effect that DWI arrests would have on alcohol related fatalities

in general, and total fatalities in particular. Most of these studies were conducted

between 1978 and 1986.

The results of these studies graphically illustrated in each state that when the number of

arrests for DWI increased, the percent of alcohol related fatalities decreased. Further,

the results of a study conducted in Florida from 1981-1983, showed that when DWI

arrests per licensed driver increased, total fatalities decreased (12 month moving

average).

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Session 2 – Detection and General Deterrence

Standardized Field Sobriety Test Course

• Deterrence can vastly exceed the level of

enforcement officers achieve

• In Stockton, increased enforcement

effort convinced at least one third of the

violators to change their behavior

substantially

Detection: Key to Deterrence

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Detection The Key to Deterrence

It is important to understand how increased DWI enforcement can affect deterrence.

Deterrence can vastly exceed the level of enforcement officers achieve on any given

night. True, weekend DWI arrests can increase by as much as 500 %, as in the

Stockton study. However, even though the study showed they started with an

enforcement ratio no better than 1 in 2000, the tremendous increase in DWI arrests

probably only brought the arrest ratio to about 1 in 400. Regardless of the fact that 399

DWI drivers avoided arrest, the increased enforcement effort convinced at least one

third of the violators to change their behavior substantially.

Session 2 – Detection and General Deterrence

Standardized Field Sobriety Test Course

When arrest/violation ratio is 1 in 400:

• Many violators WILL be caught

• General perception level of being

caught increases

• Behavior changes

Example of General Deterrence

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The law of averages quickly starts to catch up with DWI drivers when the enforcement

ratio improves to the 1 in 400 ratio. At that level, unless violators change their behavior,

many of them will be caught, or at least will have known someone who has been

arrested. Coupled with the heavy publicity given to the enforcement effort, those

experiences were enough to raise the perception level of apprehension among DWI

operators that sooner or later they would be caught. As a result, many of them changed

their behavior. This is the best example of general deterrence.

In addition, during the same time that DWI arrests went up over 500 % in Stockton,

citations for other traffic violations increased by a comparatively modest 99 %. The

implication is that Stockton's officers were stopping and contacting only twice as many

possible violators as they had before, but they were coming up with more than five

times as many arrests.

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Session 2 – Detection and General Deterrence

Standardized Field Sobriety Test Course

• Community benefits

• Officers recognize cues and clues

• Gained confidence in field sobriety tests

• Fewer violators stopped avoided arrest

Increased DWI Detection Skills

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What have the results of these studies shown? Basically, they have shown that a

community will benefit from their officers' increased skills at DWI detection. Principally

because of their special training, the officers were better able to recognize "cues" of

impairment when they observed vehicles in motion, and they were more familiar with

the "clues" or human indicators of impairment exhibited by violators during personal

contact. The officers also had more confidence in the field sobriety tests they used to

investigate their suspects. The most important factor was that far fewer of the violators

being stopped now avoided detection and arrest.

The difficulty in detecting DWI among operators personally contacted by officers has

been well documented. Analysis of roadside survey and arrest data suggest that for

every DWI violator arrested, three others actually have face to face contact with police

officers but are allowed to go without arrest. Direct support of that inference was found

in the Fort Lauderdale BAC study, where researchers demonstrated that police officers

arrested only 22 % of the DWI operators they contacted, whose BAC levels were

subsequently shown to be between 0.10 and 0.20.

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Session 2 – Detection and General Deterrence

Standardized Field Sobriety Test Course

• If violators are not arrested, attitudes

and behaviors likely will continue or

worsen

• Use resources efficiently and

improvement can be achieved

DWI Detection Ability is Key

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The ability to detect DWI violators is the key to general deterrence and possibly, the

greatest impediment to it. If we accept the three to one ratio of failed detections as

being reasonably accurate, the implications are rather alarming. Consider the impact

on a DWI violator's subsequent behavior when, after being stopped by the police, is

allowed to continue driving. Very likely, these DWI violators and their friends will

become even more convinced of their ability to handle drinking and driving. Further,

they will come to believe that they will never be arrested because police officers can't

determine when they are "over the limit." Instead of creating general DWI deterrence,

this attitude breeds specific reinforcement. This helps to develop a feeling among DWI

violators that they have nothing more to fear from police than an occasional ticket for a

minor traffic offense.

On the positive side, the ratio of undetected to detected violations suggests that much

can be accomplished with existing resources, if we use those resources as efficiently as

possible. By just being able to improve detection skills of law enforcement officers we

could experience an increase in the arrest/violation ratio of 1 in 500 without any

increase in contacts.

This same, or better, degree of effectiveness can happen here.

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Source: DWI Detection and

Standardized Field

Sobriety Testing

March 2013 Edition

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