CSI Final

4th Amendment

Protects against unreasonable searches and seizures, ensuring the right to privacy

Constitutionally Protected Locations

Persons, houses, papers, and personal effects that are secure from government intrusion

Main Purposes of Search Authority

To gather evidence, to disarm suspects for self-protection, to make an inventory of property that the police have impounded

Full Searches

Conducted to gather criminal evidence, and always requires either a search warrant or recognized expectation to the warrant requirement

Probable cause for a search warrant requires facts sufficient to justify a reasonable person to believe:

That criminal acitivty has taken place, that specific object associated with that crime exist, and that they will be found at the place to be searched

Scope of A Search Under a Warrant

The extent of areas and items that law enforcement can search as specified in the warrant

Intensity of a Search Under a Warrant

The level of thoroughness and detail with which law enforcement conducts a search, as dictated by the warrant's terms

Warrantless Search

Full searches that are permitted without a warrant include with consent, as an incident to a lawful arrest, when police have probable cause to believe a motor vehicle contains evidence that is subject to seizures, or exigent circumstances

Consent to a Warrant

A warrant is not required to search premises if the suspect or a fellow occupant consent to the search

Search Incident to a Lawful Arrest

A lawful custodial arrest carries automatic authority to search the person of the arrestee AND everything within arm’s reach for weapons and criminal evidence, with no reason to believe that either will be found

Vehicle Search based on Probable Cause

Police may conduct this of a vehicle whenever they have probable cause to believe that it contains contraband or evidence of criminal activity - Carroll Doctrine

Exigent Circumstances and Hot Pursuit

Police are allowed to enter private premises without a search warrant that create an urgent need for immediate action - must be: in hot pursuit of a fleeing suspect, threats to safety, or threatened destruction of evidence

Limited Weapons Searches

Police may perform a frisk when they have reason to believe that a person whom they have lawfully detained for investigation may be armed and dangerous

Terry v. Ohio

Set standard for brief stop and frisk based on reasonable suspicion (terry-type stop) allows police to temporarily detain and search a person

Protective Sweep

When police make an arrest inside a residence, they may perform a cursory visual inspection of closets and spaces immediately adjoining the place of arrest in which cohorts who pose a danger to the officers might be hiding

Inventory Searches

An impoundment occurs when police take custody of property for reasons other than to use as evidence, vehicles and personal belongings are taken from arrestees before placing them in a detention facility are the articles most often impounded

Plain View Exception

Permits police to perform a warrantless seizure when the initial intrusion is lawful, it is immediately apparent, the sighting is coincidental, and cannot move objects to see items hidden from view

Exclusionary Rule

Prohibits the use of evidence obtained in violation of a defendant's constitutional rights, particularly during an unlawful search or seizure

Mapp v. Ohio and Weeks v. US

Cases that involve the exclusionary rule

Internal Ballistics

Branch of ballistics that studies the behavior of a projectile within a firearm from the moment of ignition until it exits the barrel and is conducted by a forensic firearms expert at crime lab - longer the barrel, the greater the acceleration

External Ballistics

The unpowered free-flight phase of the bullet after it exits the barrel and before it hits the target, which is conducted by the CS analyst

Terminal Ballistics

The transfer of energy when a bullet hits a target and defines the path of a bullet through the target surface or body, the associated damage, and differentiating entry from exit wounds - increases in bullet velocity have greater effect on the kinetic energy increases the bullet

Close Contact

Pressed to skin

Loose Contact

Close to proximity of skin, small gap - seared skin/singed skin, triangular tears, soot, muzzle contusion, no tattooing/stippling

Close

Not more than 5 inches from the skin - soot, abrasion collar, may have tattooing/stippling

Intermediate Range

5 to 40 inches from the skin - tattooing/stippling, abrasion collar, no soot

Entrance Wounds - Bullet

Abrasion collar

Entrance Wound - Burned Gunpowder

Soot

Entrance Wound - Flame

Seared skin

Entrance Wound - Injected Gas

Triangular tears

Entrance Wound - Muzzle

Muzzle stamp/contusion from injected gases expanding skin against the gun barrel

Entrance Wound - Unburned Gunpowder

Tattooing/stippling markings on the skin

Exit Wounds

Size of wound does not differentiate entrance from the exit wounds, but the configuration of wound does - irregular borders, lacks soot, lacks tattooing

Cartridge

Single complete round of ammo - has cartridge case, primer, powder charge, and bullet/projectile

Bullet

Cooper jacket with lead on the inside

Intact

Projectile in one piece

Fragment

Projectile that is broken or shattered

Deformed

Indicates projectile damaged from its travel

Terminus

Final resting place where projectile ends up after its flight path - final target surface

Embedded

Projectile stuck in the surface it impacted

Defect

Damage produced on a target as a result of a projectile impact

Perforation Defect

Projectile goes all the way through target

Penetration Defect

Projectile does not go all the way through target

French Fry

Compressed and punched out section of foam padding creating the shape and appearance of a french fry

Glass Plate

Flat, clear, smooth surface, lacking any treatments of construction

Glass Tempered

Stress built in during manufacture upon breakage (side and rear windows)

Glass Laminated

Two sheets of plate glass cemented around a piece of plastic/laminate (windshield)

Successive Penetrations

A facture always terminates at the existing line of another fracture

Trajectory Kits

Trajectory rods, centering guides, angle finders and protractors, lasers - are tools used to determine the path of a projectile or bullet at a crime scene

Centering Guides

These can affect the angle significantly

Angle of Impact/Incidence

Use acute angle - must be direction (left/right, front/back) - complete description requires a measurement to both vertical and horizontal plane

Effects of Surface Texture

Is of paramount importance - in general, the harder and less porous the surface, the less spatter results

Rough Surfaces

Concrete, wood - usually result in irregular shapes with serrated edges, possible with satellite spatter

Direction of Travel and Angle of Impact of Blood Spatter

Tail end points to direction of travel

Angle of Impact

Sine A (second button - sin -1) = width of blood stain/length of blood stain

Area of Convergence

Is the point on a two-dimensional plane from which the drops in an impact pattern originated - drawing straight lines through the long axis of several individual bloodstains

Area of Origin

The three-dimensional location of the blood source, determined by the angles and points of convergence of the blood stains

Bloodstain Pattern Analysis Categories

Spatter and non-spatter stains + spatter stains are small, circular, and/or elliptical shaped stains - non spatter everything else

Impact Bloodstain Spatter Patterns

Occurs when an object impacts a source of blood - forward spatter is projected outward and away from the source - back spatter aka blow-back spatter is projected backwards from the source

Low Velocity Spatter

Drops with diameters of 4 mm or more normally produced by an applied force up to 5 ft/sec - associated with minimal force

Medium Velocity Spatter

Drops with diameters of 1 - 4 mm with an applied force of 5 to 25 ft/sec - usually blunt force trauma

High Velocity Spatter

Drops with diameter of less than 1 mm from an applied force of 100 ft/sec or faster - gunshot or explosions

Gunshot Spatter

is a fine forward spatter from an exit wound and back spatter from an entrance wound

Cast-off Spatter

Features are affected by the size of the object, the amount of blood, and the direction the object was moving - by counting and pairing forward/backward patterns, one may determine the minimum number of blows delivered

Cast-off Pattern

Series of related stains - linear or curvy-linear orientation - consistent parallel directional angles - result of an object which is in motion and suddenly stops

Spurt Pattern

Series of related spatter - large volume evident in the overall pattern or individual stains - EX: large elliptical stains, line of stains or overlapping stains oriented in V’s, arcs or serpentine patterns, large irregular stain exhibiting spines and spatter radiating out

Arterial Spray Spatter

Caused by an injury to the heart or a main artery and the pressure of the continuing pumping - spiked pattern, similar to EKG

Gush/Splash/Projected Spatter

Large volume accumulation with large elliptical stains and irregular stain exhibiting spines and spatter radiating out

Expectorate Blood Pattern

Created by blood that is expelled from the mouth or nose from an internal injury - mucous strands, dilution of color due to saliva, presence of air bubbles/vacuoles

Blood into Blood Pattern

Series of individual passive blood stains of blood - surrounded by a random distribution of small spatter and generally not have consistent directional angles

Satellite Patterns

Arise from blood droplets that leave the parent stain by some degree of force - small

Contact/Transfer Pattern

Created when an object with blood on it touches one that does not have blood on it

Swipes

Created when a blood-covered object moves across a surface, transferring blood to that surface

Wipes

Created by an object coming into contact through lateral motion with a pre-existing bloodstain on another object - skeletonization of OG bloodstain

Flows

Made by drops or large amounts of blood flowing by the pull of gravity - can show the movements of objects or bodies while it was in progress or after the blood dried

Pools

Blood collects on a level, undisturbed place without any specific shape, but conforming to the surface contours - collect white blood cells for DNA testing

Drop Trail Pattern

Series of drops that are separate from other patterns, formed by blood dripping off an object or injury pin - form a line or path made by the suspect after injuring or killing the victim or themselves

Void Patterns

When an object blocks the deposition of blood spatter onto a target surface or object and the spatter is deposited onto the object or person instead - blank space on a surface

Grid Method

A bunch of squares of known dimensions are set up over the entire pattern

Perimeter Ruler Method

A rectangular border of rulers is set up around each pattern and a smaller ruler next to each stain

Luminol Detecting Bloodstain Patterns

If blood was there previously, when sprayed in a certain light, it will glow bright blue - uncover attempted clean ups that are latent