Crime Scene 402 Final Exam

Evidence Linkage triangle-

1. victim

2. suspect

3. crime scene

Middle of the triangle: Physical Evidence

Physical evidence can be used to determine is a crime has or has not been committed by creating links between a victim, suspect, and crime scene

Lochard’s Exchange Principle

Every contract leaves a trace

6 things Physical evidence can do

1. Can determine if a crime has/has not been committed/establish key elements

2. Can link a suspect to a victim or crime scene (evidence linkage triangle)

3. Can place persons of interest at crime scene

4. Can exonerate the innocent

5. Can corroborate victim’s testimony

6. Can lead to confession from a suspect

Active Aggression vs Passive abuse

Active- includes but not limited to burning, slapping, kicking, shooting, stabbing, or any form of physical assault toward an animal

Passive- includes starvation, dehydration, parasite infestation, failure to provide adequate shelter, and/or obtain veterinary care

Macdonald Triad

1. bedwetting after the age of 5

2. arson

3. animal abuse

the three childhood behaviors that serve as predictors of serial killer patterns and behaviors

The 3 roles animals may play on a crime scene and how each role changes my assessment of the scene

1. Victim- collect buccal swabs, nail scrapings, and hair combings for possible trace evidence

2. Suspect-

3. Witness- collect buccal swabs, nail scrapings, and hair combings for possible trace evidence

Work the scene the same, no matter if the victim is human or animal (document everything!)

Random Search

Conducted at maximum visibility and within a small search area

Parallel Search

Best used when the area to be searched is relatively free of obstruction and close to the shoreline

River Search

Possibility is dependent on the presence of the current

Sweep Search

Most employed method for searching conducted contiguous to an accessible shoreline, bridge, dock, pier, or in a river

Circular Search

A boat-based search pattern

Snag Search

The size of the item sought and the presence of submerged obstructions determine the applicability of the procedure

Hand Searching- Explain

Used when there is low to no visibility in the water. A diver attached to a line is blindly searching the water, using their hands to feel around for items that could potentially be evidence.

The search is very difficult and almost luck-based, as you can’t see, hear, or have any idea if you’ll find evidence, or if you packaged actual evidence, until it’s already been packaged and taken to be processed.

How to package a handgun underwater

Package the gun while it is still under the water, in a plastic container, making sure the gun is covered in water in the container as well to avoid oxidizing it and damaging evidence. Dry off the packaging and apply evidence tape.

What sample should be collected from the water when collecting evidence?

Sediment/Soil sample to act as a control

The process through which a vehicle will sink

Vehicles will sink hood first, as the water enters through the vents

Vehicles that sink in water _____ than the length of the vehicle will land on the _____.

Deeper

Roof

Bodies in freshwater may _____, unless there is air trapped in the _____, while bodies in saltwater may not _____.

Sink

Clothes

Sink

With water temperatures as it relates to decomposition changes; as the water depths _____, water temperatures ______, and the rate of decomposition _______.

increase

decrease

slows down

Components of GSR

Barium

Antimony

Lead

Contact gunshot wound indicator

Burned marks on skin, stellate tearing, soot from gun

Observation upon the body associated with a hard contact gunshot wound

Star-shaped Stellate Tear in the skin

Blunt Force Trauma

stab is deeper than it is long

Cut is longer than it is deep

Laceration- tears in the skin from blunt trauma, tissue bridging

Contusion- discolorations of the skin caused by bleeding into the tissues from ruptured blood vessels

Abrasion- skin scraped away by friction

Baseline Sketch vs Compass Rose Azimuth Sketch

B- this mapping system involves a straight line that transects a scene, along which measurements are taken

C- This mapping system involves the measurement of the distance and angle (from North) of any evidence items (reference point) from a single, fixed point using a rose azimuth board

First FARO Scan should be taken where? Why?

Outside

To establish GPS coordinates

Digital Forensics

The process of identifying, preserving, analyzing, and presenting evidence found on digital devices to answer legal questions

Forensic Psychology

The systematic evaluation by a mental health practitioner of a defendant, witness, or offender for the purpose of informing the court about such issues as competency to stand trial, criminal responsibility, and risk assessment.

If you don’t document it, ___ _____ ______.

it never happened

If digital evidence is OFF when obtained, what condition should it be collected in?

OFF

Is there an expectation of privacy to digital evidence on the scene of a death investigation?

No, phone can be searched.

Before First Unlock vs After First Unlock

BFU- (bad) the most secure mode for iPhone. he file’s inside an iPhone stay encrypted until a user fills in the required password, which (if correct) is used to decrypt the file system

AFU- (good) the state of the mobile device after it has been unlocked for the first time after a reboot. The device’s data is still encrypted, but some of the encryption keys are stored in memory, making it easier for forensic tools to access data.

Three mobile Identifiers with digital evidence

1. Integrated Circuit Card identifier

2. International Mobile Equipment Identifier

3. Model Number of Phone

What is the purpose of Airplane mode for digital devices?

It removes the device from any available network, preventing evidence addition or changes

Dusky vs US

1960s court case that established competency to stand trial rules

Morphological Analysis

Systematic method of comparing features of the face

The ACE-V of facial comparison

Forensic Assessment

The application of clinical specialties,, as well as research and experimentation to legal institutions and people who come into contact with the law

Facial Identification

The discipline of image-based comparisons of human facial features

Facial Recognition

The automated searching of a facial image in a biometric database, typically resulting in a group of facial images ranked by computer-evaluated similarity

Facial Image Comparison

The manual process to identify similarities between a.) two or more facial images or b.) facial images and a subject for the purpose of determining if they represent the same person or a different person

Lights and their filters

Blue light- orange filter

purple light- yellow filter

red light- red filter

The pointed end of a bloodstain tail faces towards what?

the direction of travel

Fly Spot (BPA)

Stains resulting from fly activity

movement of flies can track blood from a body/blood source and deposit it on surrounding walls/surfaces

Patter Transfer (BPA)

A pattern created by the transfer of blood from one object to another in which a recognizable characteristic or image is present in the pattern

Bloodstains on smooth vs rough surfaces

Smooth surfaces (non-porous) result in less spatter

Rough surfaces usually result in irregularly shaped stains with serrated edges, possibly with satellite spatter

Spatter vs Non-Spatter taxonomy (BPA)

Spatter-

1. Linear Spatter- a series of related spatter stains dispersed over a surface in a linear orientation

   1. Arterial Spurt- stains created when blood is ejected in a stream under pressure, most often encountered when an artery or the heart is breeched

   2. Cast-off- Pattern created when blood is flung or projected from an object in motion, or one that suddenly stops some motion

   3. Drip trail- pattern of individual spatter deposited on a surface, demonstrating movement of the dripping item from one point to another

2. Non-Linear Spatter- A series of related spatter stains dispersed over a surface other than in linear orientation

   1. Impact Spatter- a radiating pattern of small individual drops created when a blood source is broken up by some force

      1. Expectorate- spatter created when blood is forced from the mouth, nose, or respiratory system under pressure (still breathing)

   2. Drips- Pattern resulting from blood dripping from an individual or otherwise bloodied object

Non-Spatter-

1. Irregular Margin

   1. Gush/Splash- an irregular pattern created when blood is ejected in volume

   2. Blood into Blood- a pattern created when drops are deposited into one another or into another liquid, resulting in an accumulation of blood surrounded by randomly oriented secondary spatter

   3. Smear- Any stain or pattern created by the transfer of blood from one object onto another through some form of contact involving lateral motion

      1. Wipe- Any stain/pattern created when an object moves through a pre-existing bloodstain on another surface

      2. Swipe- Any stain/pattern created by the transfer of blood from a bloodied object onto another by some form of lateral motion. Bloody object was IN MOTION and deposited the stain onto the secondary surface

2. Regular Margin-

   1. Pattern transfer- A pattern created by the transfer of blood from one object to another, in which a recognizable characteristic or image is present in the pattern

   2. Flow- The movement of liquid as a mass under the effect of gravity

   3. Pool- An accumulation of liquid blood based on gravity and conforming to the container characteristics of the pooling area

   4. Saturation- An accumulation of liquid blood created by contact with a volume of blood that is absorbed into a permeable surface

   5. Void- An area within a generally continuous bloodstain pattern that lacks bloodstains

The correlation between the angle of impact and the shape of the bloodstain (BPA)

As the angle of impact becomes more acute, the shape of the bloodstain becomes more elliptical. At approximately 90 degrees, the shape of the observed stain is consistent with a circle.

Cast off pattern (BPA)

Pattern created when blood is flung or projected from an object in motion, or one that suddenly stops some motion

SANE

Sexual Assault Nurse Examination

will conduct- thorough physical examination (collect clothes, document wounds), collect a sexual assault kit, examine for trace evidence and collect any found, examine genitalia, take oral swabs if appropriate

Time frame in which evidence from a sexual assault is likely to no longer be located or to have weakened

Evidence becomes weaker/ disappears as time passes, particularly after 36 hours

Why is physical evidence collected in sexual assault cases?

1. To establish that sexual contact occurred

2. To establish that nonconsensual intercourse occurred

3. To establish the identity of the perpetrator

A person is not criminally responsible for criminal conduct if a the time of such conduct, as a result of a mental disease or defect, he lacks substantial capacity to either:

1. appreciate the wrongfulness of their actions and accurately perceive reality to make rational and reasonable inferences (men’s rea - guilty mind)

2. conform his conduct to the law and control their behavior (actus reus - guilty act)

Mass Fatality vs Mass Casualty

MF- involves an incident where there are more dead bodies/body parts than can be located, identified, or processed for final disposition of available response resources

MC- involves an incident where the number of casualties exceeds the number of resources available from local resources

Three primary goals when attempting to manage a Mass Casualty

1. Preserve the dignity of the deceased

2. Meet the rights and the needs of the living

3. Follow requirements of government investigations

Incident Command System

TEAMWORK

ICS is when there has been an incident where many jurisdictions/agencies have to work a scene, and work it together. It’s important that the agencies use common terminology, combine resources, and supervisors handle no more than 7 people at a time. They should rotate roles as needed, so people aren’t overwhelmed/overworked.

The agencies should collectively decide how to work the scene, set up triage areas, and areas for media, family reunification, and EMS at safe locations/distances from the scene.

Three chemical requirements for clan labs

1. precursors

2. reagents

3. solvents

Three types of clandestine (clan) lab operators

1. Small-scale

2. commercial

3. educated

General rule of thumb for clan labs

If you can smell it, it’s dangerous

Clandestine Lab requirements (triangle)

1. equipment

2. chemicals

3. knowledge

Who is the best source of information at a clan lab crime scene, and why?

Cook- they like to brag