Evidence at Trial

What are the 11 Basic Steps in a Trial?

1) Court is called to order

2) Opening Statements (FIRST Prosecution, THEN Defense)

3) Direct Examination of the Prosecution witnesses

4) Cross Examination of those witnesses by the Defense

5) Prosecution Rests Their Case

6) Direct Examination of the Defense witnesses.

7) Cross Examination of those witnesses by the Defense.

8) Defense Rests Their Case

9) Closing Statements (FIRST Prosecution, THEN Defense; THEN Rebuttal by the Prosecution if desired)

10) Jury Instructions

11) The Verdict is announced

At a crime scene, unknown material needs to be identified… (2)

1) what are the ingredients

2) is this mixture common or unique

Define Chromatography

separation of colors via mixtures of dyes that are solvent in different mediums; polarity is the key factor

_______ is the most requested type of document analysis.

Handwriting Comparison

No two signatures are the ____.

same

When a document is questioned, the examiner asks for a ____. This ____ is called _____ ….or _____.

sample; sample; the standard for comparison; exemplar

What are the forms/types of standard for comparison or exemplar sample?

1) requested

2) collected

What are the 12 basic characteristics of comparison?

1) Line Quality

2) Spacing

3) Ratio

4) Lifting Pen

5) Connecting Strokes

6) Strokes begin and end

7) Unusual Letter Formation

8) Pen Pressure

9) Slant

10) Baseline Habits

11) Fancy Habits

12) Placements of diacritics

What is Placement of diacritics?

cross the T’s or dot the I’s?

What is Fancy Habits?

any unusual curls or loops or style?

What is Baseline Habits?

write on the line? Above it or below it?

What is Slant?

to the left or right? Is it pronounced?

What is Pen Pressure?

how much pressure on upward and downward strokes

What is Unusual Letter formation?

printed v. some in cursive? Different slants or angles?

What is Strokes begin and end?

where are they on the page

What is Connecting Strokes?

how are letters connected

What is Lifting Pen?

do they lift to stop or start words

What is Ratio?

of Ht, Wd, and Size- are they consistent

What is Spacing?

what is the average space

What is Line Quality?

does it flow or is there intent

What are the 3 types of prints?

1) Patent Prints

2) Plastic Prints

3) Latent Prints

What is Plastic Prints?

when prints are left in soft substances like wax, putty, caulk, soap, dust and even cold butter

What is Patent Prints?

when substances like blood, ink, paint cause a print to be left behind

What is Latent Prints?

are invisible prints need special processing or lighting

Chemicals used to find latent prints can be… (4)

1) Cyanoacrylate vapor

2) Iodine fuming

3) Ninhydrin

4) Silver Nitrate

Fingerprints are composed of ____ called ____ known as ___. ____ allow you to have _____.

valleys; grooves and hills; friction ridges; ridges; traction and grip

Importance of 1685

patterns are discovered called loops and whorls ~ Marcello Malpighi

Importance of 1823

Johannes Purkinje establishes the 9 basic patterns and the basis for the classification system

Importance of 1858

prints never change (discovery)

Importance of 1880

Henry Faulds discovers dusting latent prints exposes them and uses it to prove a person’s innocence

Importance of 1892 (2)

1) Francis Galton the first textbook on fingerprinting; he offers the convincing evidence that no two prints are alike

2) Argentina is the first country to report using fingerprints to solve a crime

Importance of 1899

Edward Henry devises the system of fingerprinting that is the basis for the current American system

Importance of 1910

Thomas Jennings is the first person convicted in America using fingerprints

What is the First Principle of finger prints?

A fingerprint is an individual characteristic; no two fingers have yet been found to possess identical ridge characteristics

What is the Second Principle of finger prints?

A fingerprint will remain unchanged during an individual's lifetime

What is the Third Principle of finger prints?

Fingerprints have general ridge patterns that permit them to be systematically classified

What is the Delta?

the point from which to start in ridge counting; in the loop type pattern the ridges intervening between the delta and the core are counted

What is the Core?

the second to the two focal points; the core, as the name implies, is the approximate center of the finger impression

Loops are found in ____ of population.

60%

A loop must have… (2)

1) one or more ridges that enter from one side of the print, re-curve, and exit from the same side

2) One Delta & One Core

Whorls are found in ____ of population.

35%

A whorl must have… (2)

1) One or more cores

2) At least two deltas

Arches are found in ____ of population.

5%

An arch must have… (2)

1) formed by ridges entering from one side of the print, rising slightly and exiting on the opposite side

2) No Deltas & No Cores

What is the AFIS?

Automated Fingerprinting Identification System

Describe the AFIS (4)

1) The computer scans and digitally encodes the fingerprints; this system allows for partial matches not requiring all ten prints

2) Can search through 500,000 prints in a second

3) Final match is still made by the human eye after the computer produces a match

4) Different states and international system are not all compatible quite yet

Over ____ of the cases of DNA exonerations have involved ______

75%; mistaken eyewitness identification

Scientists agree that memories are formed…

when neurons link together to form new connections

Describe long-term memory (3)

1) Long-term memories – stored in mental “drawers”

2) Long term memory can hold as many as 1 quadrillion separate bits of info

3) Every time you recall an event, you actually reconstruct the memory

Describe Positive Feedback (3)

1) Dynamic between victim and police

2) Victim is very, very motivated to see that crime solved (sensitivity increased)

3) Communicate unwittingly

Why do mistakes in memory happen? (4)

1) When we want to remember something, we don't simply pluck a whole memory intact from a "memory store”

2) The memory is actually constructed from stored and available bits of information

3) We fill in any gaps in the information with inferences

4) When all the fragments are integrated into a whole that makes sense, they form what we call a memory

Describe Cross-Racial Identification

Study after study shows that there is a much higher chance of a misidentification when you have somebody trying to make the identification across racial lines; we are able to distinguish features of those we're most familiar with

Things that affect memory… (2)

1) Acquisition Phase:

-Attention

-Stress

-Lighting

-Race

2) Retrieval:

-Prior expectations

-Leading questions

DNA Examples (8)

1) Blood, semen, sweat, hair

2) A weapon, such as a baseball bat, fireplace poker or knife, which could contain sweat, skin, blood or other tissue

3) A hat or mask, which could contain sweat, hair or dandruff

4) A facial tissue or cotton swab, which could contain mucus, sweat, blood or earwax

5) A toothpick, cigarette butt, bottle or postage stamp, all of which could contain saliva

6) Hair pins and hair brushes

7) Bed linens, which could contain sweat, hair, blood or semen

8) A fingernail or partial fingernail, which could contain scraped-off skin cells

What are the 3 Collection Procedures for DNA?

1) Must be placed in PAPER

2) Room Temperature

3) Label

Define Inclusions

suspect included

Define Exclusions

suspect excluded

Define Inconclusive

no conclusion reached

What is SDIS?

State DNA index system

What is NDIS?

National DNA Index System

What is CODIS?

FBI’s Combined DNA Index System; “cold hits”

The main objective of DNA analysis is to…

get a visual representation of DNA left at the scene of a crime

A DNA "picture" features…

columns of dark-colored parallel bands and is equivalent to a fingerprint lifted from a smooth surface

To identify the owner of a DNA sample,…

the DNA “fingerprint,” or profile, must be matched either to DNA from a suspect or to a DNA profile stored in a database

Many labs have the ability to conduct testing on ______, which is _______

nuclear DNA; the copy of DNA that exists in the nucleus of every cell

But only a few labs offer more specialized techniques, such as ___

Y-chromosome or mitochondrial DNA analysis

What is mitochondrial DNA?

DNA contained in structures called mitochondria rather than the nucleus

One of the first forensic methods used to analyze DNA is…

Restriction Fragment Length Polymorphism (RFLP)

RFLP analyzes the_________. These repetitions are known as _____ because they can repeat themselves anywhere from one to 30 times.

the length of strands of DNA that include repeating base pairs; variable number tandem repeats (VNTRs)

RFLP analysis requires investigators to…

dissolve DNA in an enzyme that breaks the strand at specific points

The number of repeats in RFLP affects…

the length of each resulting strand of DNA

Investigators compare samples in RFLP by…

comparing the lengths of the strands

RFLP analysis requires…

a fairly large sample of DNA that hasn't been contaminated with dirt

Describe Polymerase Chain Reaction (PCR) (4)

1) PCR is used to make millions of exact copies of DNA from a biological sample

2) DNA amplification with PCR allows DNA analysis on biological samples as small as a few skin cells

3) PCR can amplify tiny quantities of DNA and so enables even highly degraded samples to be analyzed

4) Great care must be taken to prevent contamination with other biological materials during identifying, collecting, and preserving of a sample

With RFLP, DNA samples would have to be about the size of…

a quarter

Describe Short Tandem Repeat (STR) analysis (5)

1) Smaller sample

2) Scientists amplify this small sample through a process known as polymerase chain reaction (PCR) —> PCR makes copies of the DNA (much like DNA copies itself in a cell) producing almost any desired amount of the genetic material

3) Once DNA has been amplified, STR analysis examine how often base pairs repeat in specific loci (locations) on a DNA strand

4) These can be dinucleotide, trinucleotide, tetranucleotide or pentanucleotide repeats -- that is, repetitions of two, three, four or five base pairs

5) Investigators often look for tetranucleotide or pentanucleotide repeats in samples that have been through PCR amplification because these are the most likely to be accurate

Describe Mitochondrial DNA analysis (mtDNA) (6)

1) Can be used to examine the DNA from samples that cannot be analyzed by RFLP or STR

2) mtDNA analysis uses DNA extracted from another cellular organelle called a mitochondrion

3) While older biological samples that lack nucleated cellular material (hair, bones, and teeth) cannot be analyzed with STR and RFLP, they can be analyzed with mtDNA

4) In the investigation of cases that have gone unsolved for many years, mtDNA is extremely valuable

5) All mothers have the same mitochondrial DNA as their offspring

6) Comparing the mtDNA profile of unidentified remains with the profile of a potential maternal relative can be an important technique in missing-person investigations

Describe Y-Chromosome Analysis (1)

1) Y chromosome is passed directly from father to son, so analysis of genetic markers on the Y chromosome is especially useful for tracing relationships among males or for analyzing biological evidence involving multiple male contributors

_____ is the only test in TX that state labs run. Any other test would have to be ____.

STR; paid for and run at an independent lab

STR costs ____ a test per sample and requires __ samples. YSTR costs ____ per test, and Mito costs ___ per test.

$900; 2; $1200; $2400

Potential Advantages of Banking Arrestee DNA (5)

1) Major crimes often involve people who also have committed other offenses

2) Having DNA banked potentially could make it easier to identify suspects, just as fingerprint databases do

3) Innocent people currently are incarcerated for crimes they did not commit

4) if DNA samples had been taken at the time of arrest, these individuals could have been proven innocent and thereby avoided incarceration…

5) Banking arrestees' DNA instead of banking only that of convicted criminals could result in financial savings in investigation, prosecution, and incarceration.

Potential Disadvantages of Banking Arrestee DNA (6)

1) Arrestees often are found innocent of crime

2) The retention of innocent people's DNA raises significant ethical and social issues

3) If people’s DNA is in police databases, they might be identified as matches or partial matches to DNA found at crime scenes. This occurs even with innocent people, for instance, if an individual had been at a crime scene earlier or had a similar DNA profile to the actual criminal.

4) Sensitive genetic information, such as family relationships and disease susceptibility, can be obtained from DNA samples

5) Police, forensic science services, and researchers using the database have access to people’s DNA without their consent. This can be seen as an intrusion of personal privacy and a violation of civil liberties

6) Even the most secure database has a chance of being compromised

The Federal Bureau of Investigation has chosen ___ specific STR loci to serve as the _____.

13; standard for DNA analysis

The likelihood that any two individuals (except ____) will have the same ___-loci DNA profile can be as high as ____.

identical twins; 13; 1 in 1 billion or greater

There have been approximately ____ exonerations since 1989 in US. That’s ____ years lost to incarceration, ___ exonerations thanks to DNA evidence

3302: 28,461; 566

There have been approximately ____ exonerations since 1989 in TX. That’s ____ years lost to incarceration, ___ exonerations thanks to DNA evidence

442; 2,335; 73

“Since 2006, the Innocence Project of Texas (IPTX) has worked to exonerate or free innocent people who collectively served years behind bars. …they sift through around a thousand credible letters every year from incarcerated Texans seeking to ____, either because they were wrongfully identified as the suspect or no crime occurred.

An arson conviction for a fire not started by any person is a common example of a situation that results in bogus criminal charges.”

25; 341; overturn their convictions

Ryan Commission investigation found a __ exoneration rate. What that could mean for Texans…

150,000 inmates currently incarcerated

150,000 x 6% = ____ innocent inmates!?

6%; 9,000

FBI crime lab concluded DNA resulted in ___ exclusion of primary suspect in rape and rape/homicides since 1989.

26%;

What are the top 5 leading causes of wrongful convictions?

1) Eyewitness identification

2) Faulty Forensics

3) False Confessions

4) Incentivized Confessions

5) Government Misconduct/Bad Lawyering

What problems, if any, are present with eyewitness testimony?

The Truth: memory is far from perfect

What is the CSI Effect from Faulty Forensics?

1) Jurors who want to see science in the courtroom

2) They want to see forensic applications of science

3) When state calls an expert witness to the stand who gets up there and says all of their credits, all of their resume, and all of the scientific experience that they have they're given incredible difference from the jury

What percentage of people fall into this category of CSI Effect from Faulty Forensics?

50% of the wrongful conviction cases where forensic science unvalidated science or overstated confidence has led to wrongful convictions

Which 2 groups is most susceptible to giving False Confessions?

Innocent People and Juveniles

In forensic science, define validity (2)

1) Validity refers to the extent to which a forensic technique or method accurately measures or classifies what it is intended to measure or

classify

2) It's about ensuring that the forensic science method is producing results that are accurate and reliable and that the conclusions drawn from those results are trustworthy

In forensic science, define reliability

Reliability refers to the consistency and repeatability of a forensic method or technique, meaning that the same procedures should consistently produce similar accurate results when applied to the same evidence or under similar conditions

In witness testimony, define credibility (3)

1) Credibility is the capacity for being believed; the quality that renders something worthy of belief or believability

2) A credible witness is a witness who comes across as competent and worthy of belief

3) Their testimony is assumed to be more than likely true

In witness testimony, define reliability (7)

1) Reliability is the ability of a witness to accurately know what they think they know.

2) Such reliability factors include

- the witness’s opportunity to observe the event/crime

- the witness’s degree of attention to the event/crime

- the accuracy of the description of event/crime

- the witness’s level of certainty/confidence of what they observed

- the length of time that had elapsed between the event/crime and their recall under examination by an investigator or the court