Download Crime Lab Overview

CrimeLabOverview
Melissa Valadez
Laboratory Manager
DPS Austin Crime Laboratory
Overview
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Introduction
State crime lab system
Crime lab overview (disciplines)
Toxicology overview
Questions
CrimeLaboratory
Information
Please visit us at:
http://www.dps.texas.gov/CrimeLaboratory/index.htm
Physical Evidence Handbook
Laboratory Submission Form
Customer Survey Form
Austin Crime Lab Video Tour
HB1068LabAccreditation
Effective September 1, 2005, HB1068 / Government Code
411.05 requires that the following forensic science disciplines
be accredited in order for analysis and testimony to be
admissible in court in criminal cases:
Questioned Documents
Firearms
Trace Evidence
Toxicology
Drug Analysis
DNA
ForensicAnalysis
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Controlled Substances
Questioned Documents
Computer Forensics
Audio/Video Analysis
Latent Prints and AFIS
Firearms/Toolmarks/NIBIN
Trace Evidence
DNA/Serology and CODISToxicology
DPS Crime Lab Locations
Amarillo
Lubbock
El Paso
Garland
Abilene
Midland
Waco
Tyler
Austin
Houston
Corpus Christi
Laredo
Weslaco
LocardExchangePrinciple
When two objects come into contact with
each other, a transfer of material will occur
o Material may not be detectable
o Material may be lost
o Material may be visualized and collected
Comparison of a questioned sample to a known
sample can occur or identification of material
ControlledSubstances
• Clandestine
Labs
• Plant Substance
• Crystalline
substances
• Powders
• Liquids
• Pills
• Tablets
QuestionedDocuments
Handwriting Identification
Forgery Detection
Typewriter Identification
Digital Evidence Analysis
Mechanical Printing
Identification
• Chemical Ink Comparison
• Physical Document
Matching
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• Latent Writing
Impression Restoration
• Charred Document
Restoration
• Alteration / Obliteration
Restoration
• Counterfeit Detection
• Image Enhancement
• Trash Bag Matching
QuestionedDocuments
Examination with VSC-1 reveals chemically
removed writing (right script)
Computer Forensics
Special training, skills, equipment, and
software are needed to retrieve evidence
stored within computers and computer
media to avoid alteration or destruction
• Desktops
• Tablets
• Laptops
• Cell Phones
• Storage Devices
Digital Media
Latent Prints
Patent and plastic prints are both visible prints.
However, latent prints can sometimes be visible if they
are on a highly reflective surface, such as a mirror or
chrome items.
Latent Prints
Good quality known prints are needed for comparisons
AutomatedFingerprint
IdentificationSystem(AFIS)
Searchable computer database that converts a
scanned latent print image into a mathematical
equation
AFIS doesn’t make a match of two prints, though it does
select a candidate list of those prints that are most alike
An examiner then manually compares the fingerprints of
the individuals that are on the candidate list to determine
if the two prints match
Currently we have made over 8,000 hits in our local
AFIS database and over 1,450 hits in the FBI database
FirearmsandToolmarks
• Toolmarks
• Firearms
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Functionality
Caliber and Weapon Type
Cartridge case comparison
Projectile comparison
• Serial Number Restorations
• Distance Determinations
• NIBIN
NationalIntegratedBallistics
InformationNetwork
• National Database
• Can enter cartridge cases and projectiles
from firearms, possibly linking the gun to
another event
• All firearms that are submitted to the
laboratory are analyzed for NIBIN entry
• If the firearm is returned to the owner or
destroyed, please contact the number on the
outer packaging to let us know (red sticker).
DNA/Serology
Serology
• Screening exams for body fluids
• Biological
• Alternate Light Source
• Apparent blood: Chemical
• TMB
• PHT
• Semen
• Acid Phosphatase
• Microscopic exam
(Spermatozoa)
DNA
DNA stands for deoxyribonucleic acid
The building block for the human body
½ from mother and ½ from father
Virtually every cell contains DNA
DNA in all body fluids is the same
DNA profile is consistent throughout a
person’s lifetime
• Everyone's DNA is different with the
exception of identical twins
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CODIS
COmbined DNAIndexSystem
Database of DNA profiles
FBI initiated program in 1990
TX initiated program in September 1995
Several databases of DNA profiles
Forensic evidence includes forensic unknowns and
forensic mixtures
• Generates investigative leads for law enforcement
agencies
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Texas Statistics(May2016)
Statistical Information
Total
Offender Profiles
800,076
Arrestee
55,629
Forensic Profiles
61,687
NDIS Participating Labs
16
Investigations Aided
24,535
TraceEvidence
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Hair
Fibers
Paint
Glass
• Gunshot Residues
• Shoe/Tire Impressions
• Other: Filaments, tape,
rope/cordage, unknown
substances, pepper spray,
lotions, lubricants, explosives
TraceEvidence‐ Hair
Pigment
Cuticle
Fragmented Medulla
TraceEvidence‐ Paint
Impact
Sites
TraceEvidence‐ Impressions
ToxicologySection
• Serves 31 counties for
Blood Alcohol testing
o 2015 average of 400
cases per month
o 2016 average increased
800 cases per month
• Serves all 254 counties
for Drug Toxicology
testing
o 2015 average of 650
cases per month
Blood Alcohol/Volatile
• Alcohol/Volatile Analysis
Analyze and report as detected for the
following volatiles:
• Acetone
• Isopropanol
• Methanol
• Toluene
• Formaldehyde
Drug Toxicology
• No intoxilyzer or blood alcohol testing, OR
• BAC <0.100 g/100 mL, OR
• BAC >0.100 g/100 mL and living driver with
deceased victims, OR
• BAC >0.100 g/100 mL and written request
from prosecutor with considerations
screened by Toxicology Section Supervisor
Analysis Process– InitialScreen
• Utilizes immunoassay technique (EMIT) to determine
the category or categories of drugs that might be
present
• 8 categories of drugs for both blood and urine
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Amphetamines
Barbiturates
Benzodiazepines
Carisoprodol/meprobamate
Cocaine/metabolites
Opiates
PCP
THC/metabolite
Analysis Process– InitialScreen
• Further testing after initial screen
o All EMIT results above cutoff need
confirmation for identification and
possible quantitation
o All sexual assaults
o All cases with suspected drugs that do not
respond to EMIT
Analysis Process– InitialScreen
• Common Drugs Not Detectable by EMIT
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Oxycodone (Oxycontin)
Lorazepam (Ativan)
Methadone
Diphenhydramine (Benadryl, Advil PM, Tylenol
PM)
Dextromethorphan (Nyquil, Robitussin)
Propoxyphene (Darvocet)
Valproic Acid (Depakote)
Zolpidem (Ambien)
Zopiclone (Lunesta)
Analysis Process– Confirmation
Utilize GC/MS or LC/MS/MS to determine the exact
drug present and the concentration if possible
Analysis Process– AdditionalScreening
• Utilize GC/MS and/or LC/MS/MS to look for
additional suspected drugs that did not react with
the initial screen
o One test that can identify a variety of drugs
o Can only identify, not quantify
Analysis Process– AdditionalScreening
o Includes but is not limited to:
• Anti-depressants (such as venlafaxine and trazodone)
• Pain relievers (such as methadone and tramadol)
• Muscle relaxers (such as cyclobenzaprine and
methocarbamol)
• Anti-convulsants (such as lamotrigine and valproic acid)
• Sleep aids (such as diphenhydramine and zolpidem)
• MDPV
Not TestingList
• Drugs that are generally not impairing:
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Antibiotics
Heart medication
Cholesterol/blood pressure pills
Vitamins
Acetaminophen, Ibuprofen, Naproxen
Lithium
Abilify (aripiprazole)
Cymbalta (duloxetine)
Not TestingList
• Drugs that are impairing but not currently testing for:
Psilocybin (mushrooms)
GHB
LSD
Mescaline (peyote)
Designer stimulants (except some exceptions –
mephedrone and MDPV)
o Synthetic cannabinoids
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• Even if these are the only drugs suspected, we will
still do the initial screen to determine if any other
drugs are present!
CrimeLabOverview
Melissa Valadez
Laboratory Manager
DPS Austin Crime Laboratory
[email protected]
512-424-2105 x3135