2Identifying Persons Under the Influence Nothing is a substitute for experience.Always have a “cover officer” when conducting an investigation for someone under the influence!
3Drug Addicts and CrimeStudies show that when drug addicts are jailed, burglary rates decrease.The majority of property crimes are committed by persons who have an expensive drug addiction.
4Determination of Under the Influence An officer’s determination that someone is under the influence of a controlled substance is an opinion.The only way to determine drug use is to test or analyze a sample of the suspect’s blood or urine for the presence of a controlled substance.
5Central Nervous System (CNS) Three Parts:Motor – controls things that move: muscles, eyes and internal organs.Sensory – Brain, Spine, etc.Autonomic:Sympathetic – “flight or fight.” Dilates respiratory passages and increases blood flow to vital organs.Parasympathetic – “Feed or breed.” Stimulates digestive process, slows heart rate.
6EyesPupil – is a sphincter muscle. With strong light the pupil contracts,protecting the nerve cells at the back of the eye.Iris – colored portion around the pupil.
7Eyes continued Sclera – the white portion of the eye. Cornea – the clear covering over the pupil.Retina – the rods and cones at the rear of the eye on which an image is formed.Optic Nerve – the nerve that carries visual images to the brain.
8Eye continuedHippus – is the rhythmic contraction and dilation of the pupil, may also be present in some serious eye injuries.Light Reflex – the contraction of the pupil in bright light.NystagmusHorizontalVertical
9Eye continuedHorizontal Nystagmus: the abnormal tremor of the eye while attempting to focus on an object to the far left or right while the head remains stationary.It is a clinical sign of barbiturate, alcohol and PCP use.
10Eyes continuedVertical Nystagmus – the tremor of the eye while looking up. This may also be present in persons with prior head, brain or eye injuries.Strabismus – Convergence: As the eyes follow the finger to the nose one eye will wonder off instead of appearing cross eyed.”
11Eyes continuedSmooth pursuit – the smooth, fluid uninterrupted side to side motion of the eyes when following an object from side to side.
12HomeostasisThe body follows a system of checks and balances, to maintain blood sugars, salts, water and body fluids as well as maintaining the correct body temperature.The body is always working to maintain homeostasis.
13HomeostasisWhen drugs are introduced into this balanced system, a chain of chemical reactions will occur.When determining drug influence, you must observe all these changes in body functions.Most drugs that are in a similar class (such as stimulants) exhibit similar symptoms.
14DependenceAfter prolonged drug use the body will build a tolerance to the substance.Tolerance is defined as “a diminishing biological response occurring as a result of cellular adaptation to an alien chemical.”Dependence is a state in which the mind or body craves the drug due to chronic use.The mind or body believes it needs the drugs.
15DependencePhysiological dependence: a physical reaction occurs when the drug is withdrawn.Psychological dependence: a psychological craving for the drug. (The mind wants and believes it “needs” the drug.)
16Identifying Persons Under the Influence Each individual drug has a different effect on the central nervous system.These effects can vary if used with other drugs and/or alcohol.
17Identifying Persons Under the Influence Objective (outward observable) Symptoms:Nervousness, twitching, loss of coordination.Subjective (non-observable) Symptoms:Delusions, diarrhea, sleeplessness, inability to concentrate.
18Identifying Persons Under the Influence - Eyes Stimulants and hallucinogens tend to dilate the pupils.Depressants tend to constrict the pupils.
19Identifying Persons Under the Influence When conducting an investigation for drug influence, the suspect/inmate should be watched very closely and listen to what the suspect is saying and how they are saying it.If s/he speaks rapidly or slowly, if s/he cannot stand still or has a loss of balance, can all be objective signs of drug influence.
20Identifying Persons Under the Influence Ask the subject if they have consumed any drugs.The suspect may or may not be truthful.All efforts should be made to collect a blood or urine sample.It takes time to develop expertise in determining drug influence.
21Drug Influence Testing Pupil Reaction TestPupil reaction or lack of reaction with the presence, or absence of light.A dim light should be used such as a pen light.The intensity of a Stream Light or Mag Light should never be used because it may damage the eye permanently.
22Begin the test by having the suspect stand still looking straight ahead and their hands by their sides. Measure both pupils using a pupilometer. Record the measurements. Have the suspect close their eyes for about 60 seconds, have the pupilometer ready. Have the suspect open their eyes and measure the pupils, note any differences.
23Drug Influence Testing Next, using a dim light, begin to move the light from the temple towards the eye. Note any reaction or lack of reaction of the pupil. Keep a steady, dim light on the eye for a few seconds while watching the pupil. Watch for further dilation or any rebound dilation (hippus) and record these findings.
24Drug Influence Testing Repeat with the other eye. The reason for checking both eyes is to note any natural abnormalities of the eyes or pupils.Watch for slow/sluggish reaction or lack of reaction of the pupil to the light.
25Drug Influence Testing While the suspect is standing still with their eyes closed, it is a good time to watch for other objective symptoms:Nervousness, facial grimacing, muscle tension/rigidity, eye lids fluttering, fingers trembling, facial muscle twitchesSwaying or inattention, inability to stand still and falling down.
26Drug Influence Testing When conducting drug influence testing, a control subject must be used, preferably another officer.Every attempt should be made to conduct the test under the same lighting conditions as the suspect.
27Drug Influence Testing After checking the pupils, check forNystagmusPursuitConvergence
28Smooth Pursuit TestAgain, have the suspect stand still looking straight ahead.Place an object such as a pen or your finger about one foot from the nose.Instruct the suspect to watch the object and follow it without moving his head.
29Smooth Pursuit TestMove the object from one side to the other at a rapid pace, making sure the eyes move the full range of travel.While coming back the second time, move the object slowly for the test.Watch the eyeball for tracking the object or if the eyeball involuntary jerks.
30Horizontal (side to side) Nystagmus Test Immediately after the smooth pursuit test, continue to move the object side to side.Hold the object and pause all the way to one side.Watch for involuntary jerking of the eyeball.
31Vertical (up and down) Nystagmus Place the object in front of the subject’s nose about one foot away.Move the object up and down, stopping at the top and the bottom.Look for involuntary jerking.Record your findings.
32Convergence Test Keep the object about a foot from the subject’s nose. Slowly move the object towards the tip of the nose.Hold it there for about five seconds, watching if the eyes will cross and remain crossed or if one or both eyes drift outward.Document the results.
33Rhomberg Test (Divided Attention Test) Checks the suspect’s internal clock.The Internal Clock keeps the body in a state of homeostasis.Instruct the suspect to to keep their eyes closed and head tilted back until they think 30 seconds has passed.
34Rhomberg TestDirect them to open their eyes and tilt their head forward when they think the 30 seconds has gone by.Use your watch to time the period of time.Note: If the suspect has not tilted their head forward after 60 seconds, stop the test.
35Rhomberg Test During this time: Watch for inability to stand still, eye lid tremors, shaking, twitching, repetitive body movements and swaying.If observed, note the number of inches from front to back and side to side.
36Rhomberg Test Stimulants tend to speed up the internal clock. Depressants tend to slow it.Fifteen seconds either way can be considered in your evaluation of drug influence.
37Rhomberg TestMixtures of stimulants and depressants can either speed or slow the internal clock depending on which drug in the mixture is more potent or which drug the suspect has less tolerance to.Document all objective symptoms even if contrasting.
38Pulse Rate Test Determine suspect’s resting pulse rate. An average resting pulse rate for a normal healthy individual is between 60 to 90 beats per minute (bpm).In a nervous person, the bpm is 90 to 100.
39Pulse Rate Test Depressants usually slow the pulse rate. Stimulants speed it up.Find the pulse at the wrist, count how many beats occur in 20 seconds and multiply by three.NOTE: When getting this close to a suspect, have a cover officer!
40DocumentationMost drug cases not filed by the District Attorney’s Office are due to lack of articulation.It is important to document your observations.Use agency/department forms as provided.