Forensics Exam #1

Frye v. US

("the Frye standard"); the judge decoded that scientific claims must be "scientifically established to have gained general acceptance in the particular field in which it belongs"

Forensic Engineering

- crime scene reconstruction - if a bridge broke you wanna bring them in to find out how and why it broke

Arches

- ridges enter on one side of the print and exit on the other - only 5% of fingerprints are arches

Physical Science Unit

- use physics and chemistry - soil sample, glass, paint

Latent fingerprints

A fingerprint made by the deposit of oils and perspiration; it is invisible to the naked eye Prints that are invisible and hard to see on a surface Made by perspiration and oils left behind Can be revealed by several methods (dusting and chemical)

Chain of custody

A list of all people who came into possession of an item of evidence; a record of who has the evidence and when

Henry system

A system used for classifying 10-fingerprint collections. Developed in 1899 by Sir Edward R. Henry. Used to exclude potential candidates, depending on the major factor of if different fingers have whorls on them or not. This system can only be used if you have all ten fingers, and it helps in dividing up data since it is rare to have whorls.

Physical Evidence

Any object that can establish that a crime has or has not been committed or can link a crime and its victim or its perpetrator Stuff you can put your hands on Ex: blood sample, murder weapon, body, etc.

Dermis

Bottom layer of skin; thicker layer

Applying Claims, Evidence, Reasoning

Claims ‣ someone dies from poison Evidence ‣ toxicology report shows that poison was found in his body Reasoning (why you think x,y,z happened) ‣ the drug found in the person's body is linked to detrimental effects such as death

central pocket

Draw a line between the two deltas in the plain and central pocket whorls. If some of the curved ridges touch the line, it is a plain whorl. If none of the center core touches the line, it is a central whorl

Fruit of the poisonous tree

If evidence is collected without a search warrant, it cannot be used as evidence in court

IPS

Interstate photo system (IPS) - mugshots

Forensic Computer Science

Investigate criminal use of technology and electronic records (hacker)

Ninhydrin

It is usually in a spray bottle and when sprayed onto a surface where a fingerprint is, the chemicals in ninhydrin react with the amino acids in the fingerprint and the fingerprint will turn purple (as seen in our lab)

machine learning

Many changes in the last few years machine learning/deep learning - about 128 points of comparison - Image quality is very important- it's very dependent (if you have a crappy surveillance video from a convenience store it's much more difficult for the program to match the faces)

Bertillon system

Method of identification pre-fingerprinting Consistency with his method is not good. Discovered this with Will West and William West, 1903, Leavenworth prison. They both looked the same and had the same measurements. Resulted in fingerprinting as becoming the main method of identification other than DNA.

Product Rule

Multiplying together the frequencies of independently occurring genetic markers to obtain an overall frequency of occurrence for a genetic profile Using frequency of genetic markers in the population to find the overall probability of the combination of markers Ex: One factor is found 26% of the population, another is found in 85% of the population and the third is found in 2% of the population. The probability of having all 3 is 0.25 x 0.85 x 0.02 = 0.0044 or about 1 in 200 people have all 3 of these factors.

Standard/reference sample also standard/reference/comparison sample

Physical evidence whose origin is known, such as fibers or hair from a suspect, that can be compared to crime-scene evidence Ex: sample of someone's hair and compare it to other hair; a buccal swap (check cell sample) is taken for DNA comparison

types of whorls

Plain, central pocket, double loop, accidental

Class evidence or characteristics

Properties of evidence that can be associated only with a group and never with a single source more general Items share qualities, but we don't know if they share a source

Individual evidence or characteristics

Properties of evidence that can be attributed to a common source with an extremely high degree of certainty Items came form the same source

STUDY THE FINGERPRINT IDENTIFYING WORKSHEET AND STUDY THE HOW TO IDENTIFY WORKSHEET

STUDY THE FINGERPRINT IDENTIFYING WORKSHEET AND STUDY THE HOW TO IDENTIFY WORKSHEET

First responder

Two primary duties: preservation of life, secure and preserve the crime scene and associated evidence

Maryland v. King

U.S. Supreme Court decision that endorsed the legality of collecting DNA samples from individuals arrested but not yet convicted of serious offenses

Substrate controls

Uncontaminated surface material close to an area where physical evidence has been deposited. This sample is to be used to ensure that the surface on which a sample has been deposited does not interfere with laboratory tests Materials close to location of evidence Ex: where you are looking at a surface that has a chemical on it and you want to get a sample of the same surface that does not have a chemical on it

Iodine fuming

When a material is suspected to have a fingerprint on it, it is put into an enclosed cabinet where there are iodine crystals. The iodine crystals are heated to where the suspected material is exposed to the iodine vapors and in turn, this will make the latent print visible.

Superglue

When a non-porous surface is exposed to cyanoacrylate vapors such as super glue, and development of fingerprints with this method occur when fumes from the glue adhere to the latent print and the print will appear white.

Powder

When applied lightly to a nonabsorbent surface with a brush will adhere to residues and deposits of body oils that are on the surface. Different colored powders are used depending on the color of the surface so that the color of the print will pop when exposed to the powder. Magnetic sensitive powder by using a Magna Brush is what we used in lab and has no bristles so there is less of a chance the print will be destroyed.

The CSI Effect

When viewers of crime-related television shows claim a level of expertise CSI viewers generally have higher evidence expectations than non-CSI viewers Basically the effects that are seen with people who watch crime-related television shows

Biometric matching

a cutting- capable of identifying someone out of a crowd by scanning select biometric characteristics into a database. Law enforcement entities implement this form of biometrics to find wanted fugitives and individuals suspected of terrorism - Tailored for law enforcement or government institutions that are seeking a person of interest - Makes it harder for wanted individuals to elude the law and hide among the public

Anecdotal Evidence

a story that someone tells to support their case, but it's just one (or a few) cases (Ex: someone you know has an allergic reaction to a vaccination. That's not enough evidence to say that everyone will have an allergic reaction)

biometric identification

access control; can distinguish between subjects by analyzing a biometric trait of one person and compare it against an existing database of enrolled - Apple iphone is capable of identifying an individual for the purpose of entry - Access control systems will create and store databases of biological traits and compare them to the individual attempting to gain entry into a device of facility - With the use of a facial or retina scan, the system will decide who can gain entry to a facility or device with extreme accuracy

facial recognition

aims to accomplish this goal in a more efficient manner that does not need the assistance of the public - Used for identifying wanted and missing people, user-access control and credential management - Not intrusive and can gain data in a way that is comfortable and hygienic for its users it can be easily tricked by a 2D pic, its harder to categorize and analyze an entire human face; complex models and graphs need to be stored which slows down the processing speeds

Reasoning

applying scientific logic; explaining it using science; explaining the science and the logic Example: fingerprints are unique and don't change overtime and there are millions of fingerprints

Biology Science Unit

blood samples, plants, carpet fiber, hairs

retina

composed of neural cells in the back of the eyeball that provide a "screen" for the cornea and lens to display an image on; responsible for obtaining a clear picture of what a person is actually seeing - A long series of views and capillaries is contained within retina, and just like the muscle fibers in the iris - Problems with retina biometrics is that viable images can be affected by disease

plain whorl

consists of one or more ridges which make or tend to make a complete circuit

accidental whorl

contains two or more patterns (not including the plain arch, or does not clearly fall under any of the other categories

Daubert v. Merrell Dow Pharmaceutical, Inc (Daubert

dauber's parents alleged that the bendectin his pregnant mother had taken had caused the child to suffer a birth defect - The drug companies expert testified about published studies that showed no fetal malformations, while the plaintiffs eight experts offered the unpublished results that were conducted on animals, not humans - The parents lost, so they appealed(appeal didn't work) - SCOTUS made new guidelines, scientific methods and procedures should be clearly established in the field - Judges will now determine whether the theory is testable, its potential horror rate is known, it has been peer reviewed, and it is relevant to the case

Federal Rules of Evidence (FRE)

dropped "general acceptance" in lieu of knowledge, skill, training, or experience, and allowed judges to decide on relevance - This opened the door for investors to claim that "novel" methods unknown to their peers were nonetheless scientific - ex: are lip prints like fingerprints? A lip print taken by duck tape was used to convict a man for murder - It was later deemed "junk science"

Toxicology

drugs and poisons

Trace Evidence

evidence that you need special techniques to see or locate because it is very small (Ex: hair, fibers, DNA, and fingerprints)

FACE

facial analysis, comparison, and evaluation(FACE)- visa applications and driver's license photos

Claims, Evidence, and Reasoning

framework used to analyze information ‣ someone dies from poison ‣ toxicology report shows that poison was found in his body ‣ the drug found in the persons body is linked to detrimental effects such as death Know how to apply

Firearms Unit

investigates discharged bullets, cartridge cases, shotgun shells, and ammunition

Correlation vs. Causation

just because one thing ties/is related to another, thing does not mean that thing causes the other thing

Polygraph unit

lie detector test

Document Examination Unit

looks at types of paper, ink, handwriting analysis, forgery

radial

loop open toward the left or the radius bone

ulnar loop

loop open towards right or the ulna bone(On the left hand, a loop that opens to the left would be an ulnar loop while one that open to the right would be a radial loop)

double loop whorl

made up of any two loops combined into one print

false positives

many variables can throw the results of facial recognitions off - simple obstructions like glasses, contacts, hats, facial hair, and hooded sweatshirts are able to throw off the results or simply prevent the camera from procuring usable data - unlike iris biometrics, facial recognition focuses on a part of human body that changes dramatically over time and can be manipulated or disguise easily to spoof the automated computer ex: Jose Salvador Lantigua (faked death for insurance claim--> created a new alias and wore a brown tupee and dyed beard--> didnt get caught until he applied for a passport with a picture

NPPS

national palm print system (NPPS)

Causation

one thing causes another thing

Correlation

one thing is related to another

Epidermis

outer layer of skin with ridges

Crime scene investigator

person in the field; actually at the crime scene

Criminalist/Forensic Scientist

person in the lab; they do dna analysis, chemical tests on paint. etc.

Evidence

physically what is there that supports the claim

forensic psychiatry

profiler

Ridge characteristics/minutiae

ridge endings, bifurcations, enclosures, and other ridge details, which must match in two fingerprints in order for their common origin to be established; little details of the fingerprint

plain arch

ridges enter on one side and exit on the other side(only 5% of fingerprints are arches)

tented arch

similar to the plain arch, but has a spike in the center; the spike is like a tent pole(only 5% of fingerprints are arches)

Testimonial Evidence

statement made by a person Ex: witness statements, alibi's, character witness

Claim

statement you are trying to support

Criminologist

study people who are accused of committing the crimes; more related to the sociological study of the justice system

forensic odontology

teeth

Types of Arches

tented and plain arch

iris

the colored section in the eye around the pupil; unique to every human being and consists of tightly grouped muscle patterns that are stained green, blue, brown - The intricate muscle patterns and iris construction is unique to every person - Problems is that contact lens or glasses can effect the biometric Iris is replacing retina biometrics (all around better technology)

Friction ridges

the markings on the fingertips that leave oily fingerprints on surfaces we touch

Melendez-Diaz v. Massachusetts

the necessity for the forensic scientist to appear in court has been imposed on the criminal justice system; addressed the practice of using evidence affidavits or laboratory certificates in lieu of in-person testimony by forensic analysts

Comparison

the process of ascertaining whether two or more objects have a common origin

Identification

the process of determining a substance's physical or chemical identity. Drug analysis, species determination, and explosive residue analysis are typical examples of this undertaking in a forensic setting

physiological biometrics

this form of biometrics focuses on identifying humans through their unique physiological traits; includes fingerprints, hand, iris, retina, and facial scans - Fingerprints Most cost efficient and easy to install - Facial scans are the least accurate form of biometrics - Retina and iris scans is much more secure than the use of fingerprints due to the detailed map of the eye

behavioral biometrics

this form of biometrics focuses on identifying humans through unique behavioral or mental patterns they exhibit; includes handwriting, voice, keystroke, and gait recognition(the cycle of walking) - Concerned with the way a human performs an action

Crime scene investigation/evidence collection

trained personal that are dispatched to the crime scene to try and collect and preserve physical evidence that will later be processed at the crime lab

Types of Loops

ulnar and radial loop

Photography Unit

uses photography to support evidence in a legal case in a court of law

Identification vs. Comparison

you know the exact identity of the substance (ex. DNA from one person) vs. you know that two substances are the same as one another (ex. same type and color of paint)

Voiceprint Analysis Unit

§ in cases involving telephoned threats or tape-recorded messages, investigators require the skills of this unit to tie the voice to a suspect

Whorls

◦ they have at least one ridge that makes (or almost makes) a complete circle ◦ Has at least two deltas ◦ If a print has more than two deltas it is most likely an accident ◦ 35% of fingerprints are whorls

Loops

◦ they must have one delta (triangles) and one or more ridges that enter and leave on the same side ◦ patterns are named for their positions related to the radius and ulna bones when on the surface (not on the hand) ◦ 60% if fingerprints are loops ◦ most common