all of csi

marks and impression - tyres

• fitted to a range of vehicles

• tyre mark data base - 8500

mark and impressions - tread

• show dimensions and a design of individual types

• impression evidence

mark and impressions - visible 2D

• left in substrate

• tyre leaves behind residue/marks on surfaces

mark and impression - impressed

• 3D negative prints - tyre tread impressed into a soft substance

• measurements taken

• cast the marks

• snow wax or hairspray to secure mark in snow

glass

float - windows and doors

toughened - windows and doors

laminate - vehicles

patterned - churches

wire-reinforced - security doors

container - glass bottle

fibres

• fibres are the individual filaments from which textiles are composed

• most textiles will transfer their component fibres when they come into contact

• they are the most frequently encountered type of trace evidence

• natural fibres - derived from plants and animals

• synthetic - produced from polymers

factors affecting transfer

• the amount of pressure at the time of contact

• the length of time the contact occurred for

• how many times contact was made

• the texture of both the do not and recipient garments

recovery of fibres

• photography

• recover whole item if possible

• fibre taping

  Use wide tape – place onto acetate

  All fibres to be on tape, not over the edge – add tape if necessary

  Details to be completed on acetate - bag

  If necessary pull out fibres/tufts

hairs

• photograph as always

• document if there’s a root or not

• individual/clump - use tweezers

recovery of hair from suspect

• for DNA analysis - 3 individual hairs of same type with root

• dor drug analysis - at least 30 hairs with root from the head

paint

• obtain sample from as close to damaged area as possible

• new scalp blade

• control sample from undamaged area

tools

• have a unique marking/defect

• tools can deposit pain

• they have serial numbers

tool impressions

• can link a tool to a crime scene

• link suspect to crime

• provide other evidence types

recovery of tool marks

• photograph

• use a casting material to make a duplicate of the mark

• recover wrap in cortex or tissue

backward glass fragmentation

• when glass is broken a quantity of it will fly back in the direction it was broken from

• concentric fracture - compression

• radial fracture - tension

police and criminal evidence act

1984

• powers of arrest and detention - can arrest without warrant if they have reasonable grounds, suspects can be held up to 24 hours without charge

• questioning a suspect - suspects are informed of their rights

• search powers - grants police authority to search under certain conditions

• evidence handling - rules on gathering and handling evidence

• code of practice - PACE supported by detailed code of practice guides police on proper procedure, detention, questioning and searching

human rights act

1998

• rights protected - right to live, fair trial, freedom, privacy

• effect on uk law - public authorities must act in a way that protects rights, if they violate these can be challenged in court

• interpretation of law - interpret law in a way its compatible with rights

criminal procedure and investigation act

1996

• disclosure of evidence - requires both prosecution and defence to disclose evidence that may assist in proving a case of undermining other party

• investigation procedures - rules for how investigations must be conducted, requires to retain evidence that could be relevant to a case and review periodically

• handling of evidence - framework for handling and disclosure of evidence ensuring fairness aiming to prevent miscarriage of justice

• impact of trials - failure to disclose important evidence could leaf to exclusion of that evidence from the trials or the case being dismissed

forensic science regulator act

2023

• role of regulator - ensure forensic practice are carried out to high standard

• standard and accreditation - gives regulator authority to set quality standards

• oversight - overseeing forensic providers and ensuring they follow best practices

• improving accountability - aims to reduce errors or wrongfully convicted due to substandard forensic practices

health and safety at work act

1974

• employer responsibility - employers required to provide safe environment, conduct risk assessment, implement measures and appropriate training

• employee responsibility - take care of their own safety and others affected by their actions

police act

1997

• police complaint authority - overseeing complaints against police, ensuring accountability and transparency

• national crime squad - tackle serious and organised crime

• power of arrest and investigation - expand certain police powers related to arrest an investigation of suspect

PPE at work act

1992

• employer responsibilities - provide suitable PPE and proper training, replace PPE when necessary

• selection of PPE - selected based on specific risks present

control of substances hazardous to health act

2002

• risk assessment - employers required to carry out risk assessment to identify hazardous substances

• control measures - implement control measures to reduce exposure

• health surveillance - for certain substances employers must monitor workers who may have been exposed

• training and info - employers must provide appropriate training and info about the risks with substances

risk assessment

risk - probability of something happening

hazard - anything which has the potential to cause harm

exposure - length of time something is exposed to something else

control measure - procedure or precaution put in place to reduce the risk or harm

first actions on arrival

• establish type of crime committed

• speak to ant person in attendance to gather as much info

recovery

• only one opportunity to recover evidence

• thorough and logical examination needs to take place in sequential manner

• actions at this stage can impact whole investigation

initial action prior

• info gathering

• checking police log

• specking with injured party

• talking with officers in charge

sequential processing

• no correct way to examine each scene

• visual examination

• recording

• evidence recovery including packaging

• search for latent evidence

• walk through and final visual examination

visual exam

• consider the least likely approach

• establish mode of operation

• consider health and safety risk or potential hazards

• ensure the scene has been appropriately preserved

establishing a MO

• type of crime committed ]type of property attacked

• how the offender has entered and exited the property

• a description of method of entry

• where the offender had been in the property

• what has been stolen

main categories

• crimes against a person

• crimes against society

• acquisitive crime

volume crime

• offences that occur frequently but often considered less serious

• high numbers but involve less criminal activity

major crime

• requires senior investigator officer and support major incident room

• larger staffing/resources and specialist skills from outside the force

,,

…

skills

• communication

• decision making

• empathy

• observation

• initiative

• leadership

intelligence

• collection of info that may further an investigation

• specific method of operation

• type of footwear pattern, tools, property stolen

• helps links scenes, develops a timeline of events

major cimes

• requires the appointment of a senior investigating officer

• requires large staffing and may need expert skills

how is a crime reported

• attendance of front desk

• call to police

• crime stoppers

• referral by agencies

• text/email

after a crime reporting

• contact handler

• create incident log

• assess the seriousness of the crime

• prioritise police attendance

• send electronic log to radio dispatcher who will asses availability of police and deploy officers

international organisation of accreditation standards and accreditation

• signing of the code of conduct

• standard operating procedures

• competency testing of CSIs

• dip sampling of scene reports and scene images

• direct observations

• ensure correct storage of consumables

5 building blocks

• preserve life

• preserve the scene

• secure evidence

• identify victim

• identify suspect

forensic strategy

• volume crime - basic level and csi will decide

• major crime - larger scale, to be discussed

• a clear set of objects required for each sample or exhibit recovered

• helps to prioritise how each sample or exhibit is examined

police and criminal evidence act

• provides code of conduct around how police powers can be utilised

• 8 codes of practice

• c detention, treatment and questioning of suspect in custody

• d relates to the identification of people in connection with the investigation and keeping of accurate criminal records

PACE code C

• detention, treatment and questioning of persons by police officers

• becomes relevant to csi as they may be asked to act as

  designated person

  someone other then a police officer

  they have some under the police reform act 2002

  powers allow them to search suspects and take samples with reasonable force when authorised

PACE code D

• identification of people in connection with the investigation

• need to keep accurate records

• samples that can be taken from a detainee in custody

• code clearly defines the difference between intimate samples and non intimate samples

intimate samples

• photographs - private areas, clothing, no member of opposite sex present

• samples of blood, semen, pubic hair, urine

IDENT 1

• current uk fingerprint database

• supersede national automated fingerprint info system

• provides all forces to a national database of the ten-pint records of all convicted criminals

non-destructive techniques

• search and recovery of all evidence visible evidence

• no additional techniques to enhance or recover

• no introduction of contaminants

why is packaging important

• to avoid contamination

• to avoid health and safety issues

• start of continuity chain

• ensure integrity of item

packaging mediums

• tamper evidence bag

• brown paper bags

• cardboard boxes

• universal sample containers

• weapon tubes

• nylon bags

biohazard tape

any items that poses a biological threat needs to have either biohazard tape or sticker

continuity

• maintaining the factual record which documents the possession, movement and where about of evidence

• every time an exhibit is passed to another the label is signed and dated

integrity

• the exhibit cannot be contaminated, damaged or tampered with in any way

• gives justice system confidence nothing untoward has happened to exhibit

injury photography

• assault

• sexual offences

• child abuse

• domestic violence

• complaint against police

• attempted murder

reason for injury photos

• inform police

• evidence my heal before court

• visual representation

• definitive evidence

conduction of injury photos

• consent must be given by victim

• under 18 need parental consent

• try get a photographer of a gender the ip is comfortable with

• never touch the person

• clothing removed by ip or medical staff

• first shot always head shot

• long, mid close ups

bite marks

• can be matched to the teeth of a suspect

• series of images with and without scale

• several sets of images over time

types of vehicle crime

• Criminal damage

• Theft from motor vehicle (TFMV)

• Theft of vehicle – Stolen Motor Vehicle (SMV)

• Taken without owners consent (TWOC)

• Vehicle Used in Crime (VUIC)

• Arson

theft from vehicle

• fuel

• parts

• in car entertainment

• alloy wheels

theft of a vehicle

• Steal for commercial gain (organised crime)

• Steal for cutting up (“ringing”)

• Steal for joyriding

• Steal to use the vehicle in the commission of another crime

vehicle security improvement

• unable to hot wire new vehicles

• unable to pick/ force lock

• unable to bend door from frame

DNA17 and contamination

• DNA17 is very sensitive and can generate a profile from small qualities

• increases sensitivity has lead to the need for increased ant contamination measures

• potentially more issues of secondary transfer

transfer of evidence

• primary - the direct transfer of material from one object to another

• secondary - the indirect transfer of material from one object to another via intermediary object

anti contamination

• avoid touching face, sneezing or coughing when collecting DNA

• do not eat, drink, smoke when handling samples

• do not talk near or over DNA evidence

• change gloves after every collection of each

sample collection

• all items packages separately

• always best to recover the whole item if possible

• item to be securely sealed at the scene

• all exhibits labels or bags to be filled in fully

• all bags to have biohazard tape/sticker

sample collection - swabbing

• check all swabs are from the same batch and are in date

• ensure swab tube and water ampule are secure before use

• at major crimes take a control swab and a water control wetter with water

limitations to DNA

• not possible to establish when DNA was left at the scene

• was the DNA deposited as a result of direct contact?

• was the DNA deposited as a result of secondary transfer?

• susceptible environmental factors

• certain medical conditions

why do we record crimes

• accurately records all findings at a crime scene

• start of continuity chain

how do we record crime scenes

• contemporaneous notes

• diagrams

• videography/photography

sequential processing

1. visual examining

2. recording

3. evidence recovery including packages

4. search for latent evidence

5. walk through and final examination

notes should be

• accurate

• comprehensive

• relevant

• factual

• dated

common errors in note taking

• forgetting time and date

• incomplete sections

• sampling out of order

• signatures

3 Pilars of photography

ISO - sensitivity of camera to light

Aperture - opening of lens to control amount of light entering

Shutter speed - length of time camera shutter is open

ISO

• as you increase the number the brighter the photo will be

• 100,200,400,800,1600,3200,6400

• photo taken at to high of a number will show a lot of grain

aperture

• larger the f number the smaller the diameter

• low numbers = wider aperture

• low numbers = smaller aperture

• range F8-F16

Depth of field

everything which appears crisp and clear, other than, but also including the point
of focus

crime scene photography

general images - routes and entry points

long - further general views of the scene but begin to locate evidence

mid range - focuses on item or interest but still shows surroundings

close up - shows evidence in greater detail

evidence recovery destructive techniques

• Search and recovery of latent evidence

• Introduction of contaminants

• Powders and chemicals

• Focus on fingerprint and footwear evidence

friction ridge details

• fingerprints are made up of ridges, furrows and thousands of tiny sweat spores

• assist sense of touch

• ridges cause friction which allow for grip

fingerprint patterns - Loop

• 65% of fingerprints

• sufficient recourse

• one delta

• ridge count of at least one between the delta and core

fingerprints patterns - Nutant loop

• the course of the loop bends, turns down other drops towards the delta

fingerprint patterns - Ulnar

• 94%

• when the loop enters and exits from the little finger side of the hand

fingerprint patterns - Radial

• 6%

• when the loop enters and exits from the thumb side of the hand

fingerprint patterns - plain arch

• ridges run from side to side

• no delta

fingerprint patterns - tented arch

• ridges near the centre have an upwards thrust

• appears as the tent in outline

fungerprint pattern - whorl

• 30%

• at least on circuit of ridge formation completes 360

• circuit may be formed from a continuously flowing ridge or by segments from several ridges

• 2 deltas

fingerprint patters - twinned loop

• 2 well defined loops

• one surrounding the other

fingerprint patterns - lateral pocket

• 2 loops with the same directional shape

• the uppermost loop nutant, forming a pocket, filled by the underlying loop

fingerpint pattern - composite

• a complicated combination f patterns with 3 or more deltas

fingerprint patterns - accidental

• a minority pattern which does not conform to the arch, loop of whorl types

• possesses characteristics common to all 3 types

how are items deposited

• deposited onto an item in a contaminant

• impresses into an item

• deposited into an item in sweat

search and recovery

• initially conduct a visual examination

• photograph scene and location of fingerprints

• impresses fingerpints

• laten fingerprints

latent marks

• quality of the print depends on surface, pressure, age, time and storage

• powders - metalic flake, granular, magnetic

• brushes - carbon/glass fibre, animal hair, feather, synthetic, magnetic wand

• lifting medium - codex sheet, template, scalpel, touch, permanent pen, roller

laten mark examination

• fingerpints to be done after DNA and trace evidence examination completed

• work cleanly, keeping damage to a minimum

• photograph all locations of fingerprints before lifting, recovering

• would not leave own prints as wearing gloves

• start at the point go entry and be systematic

footwear marks can be …

• as unique as fingerprint

• help build up a picture of events

• prove or disprove accounts given by suspects and/ or witness

• indicated the number of suspects at a scene

• leads to the identification of suspect

forms

• 2D surface transfer marks - footwear marks left on surface, not visible, may need enhancement

• three dimensional impressions - footwear impressions are left in a surface

recovering 2D marks

• always photograph if visible

• if you can recover whole item

• electrostatic lifting apparatus

• enhancement with powers

• gel lifting

3D scanning

• currently being trialled is a 3D printer for footwear impressions

• scan the footwear impression and a printer will produce a dense and accurate surface model at the scene