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OR – Saltash.net Community School

UNIT 32: FORENSIC EVIDENCE COLLECTION AND ANALYSIS

Assignment Tasks

And

Scheme of Work Overview

Learning Outcomes

On completion of this unit, a learner should:

1 Be able to gather ‘forensic’ evidence from a simulated crime scene using appropriate methods and present the results

2 Understand the chemical techniques used in the analysis of evidence from a crime scene

3 Understand the physical techniques used in the analysis of evidence from a crime scene

4 Understand the biological techniques used in the analysis of evidence from a crime scene

This what the students will learn during Unit 32, this contains information for P, M and D levels.

1 Be able to gather ‘forensic’ evidence from a simulated crime scene using appropriate methods and present the results

Documentation: collecting; recording; storing and distributing data by electronic means

Evidence: targeting and recovery of trace materials; characterisation and comparison; marks and impressions

Health and safety: eg Health and Safety Act 1974; eg COSHH Regulations 1996; eg Management of Health and Safety at Work Regulations 1992; disposable protective clothing

Preservation of scene and sampling: observation and recording of the scene; restriction of access; search for material of potential evidential value; packaging and labelling; storage and transmission to laboratory

Analysis and evaluation: prevention of contamination; security; records; full documentation of procedures and methods

2 Understand the chemical techniques used in the analysis of evidence from a crime scene

Spectrometry: instrumental techniques; mass spectrometry; infrared; ultraviolet; colorimetry

Chromatography: separation of mixtures eg paper, column, thin layer (TLC), gasliquid (GLC), high performance liquid (HPLC)

Toxicology: science of poisons; detection; effects; antidotes


3 Understand the physical techniques used in the analysis of evidence from a crime scene

Audiometry: instrumental methods of recording sound information

Photography: images of traffic; surveillance; public order offences; support team at major incidents; high quality record of exhibits eg taking devices apart

Ballistics: interior and exterior ballistics; firearms; cartridges; calibre; discharge; residue

Electronics: electronic imaging; enhancement techniques to improve photography and video; television monitors; cameras; alarms

Metrology: study of weights and measures

4 Understand the biological techniques used in the analysis of evidence from a crime scene

Analysis: paper; entomology; genetics (DNA sequencing, genetic fingerprints)

Histology: study of tissues and tissue types; fingerprints (four basic patterns); blood group analysis

Skeleton and anthropology: physiology of bone and skeleton

Microscopy: measurement and comparative microscopy


Contents Page.

Page 2 – 3. Learning Outcomes and Unit Content. Contents Page.Page 5 . How to use these assignments


How to use the assignments.

In each assignment there are the same forms, below is guidance on how each form should be used.

1. Teachers Level Sheet (one for the whole unit) – this lists the requirements that each student needs to complete in order to pass that level, this is the gold standard of what a Pass, Merit and Distinction are. If students meet these even though they don’t complete all the tasks then they still pass. These are used as the objectives

2. Student Cover Sheet (one per assignment) – gives the student the information on the assignment and what the big picture is. The start date and target completion date need to be filled in before handing to students and this needs to be signed and dated by you when they complete the assignment. This needs to goon the front of each assignment.

3. Student tick list (one per assignment) – gives objectives (blue boxes) and lists the outcomes (in the tables) that the student needs to complete in order to meet each level. Care has been taken to ensure that if a student completes all the tasks then they will have met all the objectives. This also needs to be signed by you and the student for each level and submitted with the work. There is space at the bottom to show what the student needs to do to either complete the level or move onto the next one.

4. Lesson guidance (one per assignment) – lists the activities that should be completed in each lesson. This is guidance only. All students will have a paper copy of the big picture, objectives and the outcomes from the two sheets above but you may still want to display these to the whole class.

5. Resources (one per assignment) – any resources needed to complete the tasks, will be referred to in the lesson guidance.


Teachers Level Sheet – Unit 32 Forensic Science


Student Cover Sheet.

Forensic Science– Assignment 1

Student Name Group

Big Picture

A forensic investigation requires several different professionals who each play a role in the case. During this assignment you will look at the roles of Scene of Crime offers and Forensic scientists

Level BTEC National Award and CertificateCourse Title Applied Science

Unit Title Unit32: Forensic ScienceAssignment Number 1 (P1,M2, D,1,)

Topic or ThemeScenario

You have just been accepted as a trainee forensic scientist. Your first task in this position is to prove what you have learnt so far in training but also on the job. You must produce a portfolio of your work so far that highlights how to collect and analyse data. If you can prove yourself then your employee is willing to allow you to attend the scene of a crime and assist in the collection and analysis of evidence.

For this you will be required to write a report of how you collected and analysed the evidence. You will then need to draw and justify your conclusions in the report which will later be submitted to court.

Task one – collect evidence from crime scene as a SOCO

Task two – Analyse evidence from a crime scene as a Forensic Scientist

Task three- Write a report of your finding to be submitted to court

Good luck on your first case

Date issued Date Submitted

Signed by Teacher

Signed by Student


Task one – Gathering evidence from a crime scene student tick sheet


P1 carry out a forensic examination of a simulated crime scene, using appropriate methods to gather biological, physical and chemical evidence

Teacher Comments for Improvement

D1 justify the procedures used to gather evidence from a simulated crime scene

M1 describe the procedures used to gather evidence from a simulated crime scene

Arrive at crime scene and carryout the following steps

Secure crime scene using appropriate equipment Sketch and photograph the crime scene Correctly mark and photograph evidence found at crime scene using

either quadrant, link, strip/line, grid, spiral or wheel method Collect evidence found at the crime scene using the appropriate

equipment

Collect the teacher observation form

Produce a report of how you collected the evidence using your photos. You should write a brief description of what you are doing in each pictureYour report produced for P1 must describe fully each procedure and piece of equipment you used to secure and collect evidence from the crime scene. This should include use of protective clothing and health and safety

Show clear diagrams in your portfolio of how forensic scientists gather evidence from a crime scene. This should include how evidence is documented, transported and stored. You must include the following; Note-taking, Sketching, photographs, targeting and recovery of evidence, packaging and labelling

Summarise the following terms and describe the importance of each; Common approach path, Contamination, Cross contamination, Gel filter, Chain of continuity, Latent, First attending officer, restriction of access

Complete worksheet 1

In your report you must justify the procedures and equipment used in the collection and gathering of each evidence. This should include what would happen if you did not follow procedures in terms of safety and contamination.

Explain three alternative methods/equipment that you could have used to better your investigation

Discuss the term over looking evidence and how this risk can be reduced by using the right methods correctly

Task two – Analyse evidence from a crime scene as a Forensic Scientist


P2 outline the main techniques used to analyse chemical evidenceP4 outline the main techniques to analyse physical evidenceP6 outline the main techniques used to analyse biological evidence

P3 carry out practical work used to analyse chemical evidence gathered from a simulated crime sceneP5 carry out practical work used to analyse physical evidence gathered from a simulated crime sceneP7 carry out practical work to analyse biological evidence gathered from a simulated crime scene


Teacher comments

Briefly describe the following chemical techniques and how they could be used to analyse evidence

Spectrometry Colorimetry UV and IR spectroscopy Chromatography Chemical enhancement Chemical presumptive tests toxicology

Briefly describe how the following physical techniques and how they could be used to analyse evidence

Photography Ballistics (guns, microstamping, discharge residue, wound patterns,

trajectory) Document examination (handwriting, signatures, printed

documents)

Briefly describe the following biological techniques could be used to analyse evidence

Blood group analysis DNA sequencing Fingerprints Hair and fibre Bones and skeleton physiology microscopy

Followed methods for the different analytical techniques outlined above and have a completed teacher observation sheet for the experiments

Follow your plans above to analyse the pieces of chemical, biological and physical evidence found at the crime scene

Record your results accurately in a suitable format

Analysis of evidence Merit Criteria

Analysis of evidence Distinction Criteria


M2 explain the main techniquesused to analyse chemical evidenceM4 explain the main techniquesto analyse physical evidenceM6 explain the main techniquesused to analyse biological evidence

M3 present valid conclusions drawn from the analysis ofchemical evidence gathered from a simulated crime sceneM5 present valid conclusions drawn from the analysis of physical evidence gathered from a simulated crime sceneM7 present valid conclusions drawn from the analysis of biological evidence gathered from a simulated crime


You must give a detailed explanation of all the major techniques that you described in P2,4,6 (the chemical, physical and biological techniques) You will also need to

Give two examples of when forensic scientists may use the methods given

Give an appropriate example of your forensic application to the simulated crime scene

Using the information you have gained in P1 you must now plan how you will analyse each item of evidence from the crime scene. This will need to be represented as a method sheet

You must draw conclusions from each analysis that you have carried out. This needs to

Link suspects to the evidence Eliminate suspects from the evidence Use the evidence and data in the conclusion

Make sure that you support your conclusions with evidence and reasoning. You must do this for the Merit

Task three- Write a report of your findings to be submitted to courtOR – Saltash.net Community School

D2 evaluate the techniques used to analyse chemical evidenceD4 evaluate the techniques used to analyse physical evidenceD6 evaluate the techniques used to analyse biological evidence D3 D5 D7 justify the choice of techniques used to analyse the chemical, biological and physical evidence gathered


Evaluate all of the techniques that you have used in your investigation and explain why the techniques used were suitable

Justify your choice of equipment and whether you would use the same apparatus/technique again and if so or not explain why.

Discuss alternative techniques that you could also have used explaining how they could have assisted your case

In your portfolio you will need to produce a table that discusses the advantages and disadvantages of each method that you have used. This will need to be off all methods outlined in P2,4,6.

Explain how the techniques you have used could be applied to different types of criminal investigations

Lessons and dates

Learning OutcomesYou should be able to:

Activities Homework

1

Introduction to unit Introduction to unit and learners booklet passed out. Deadlines given

Practical – every contact leaves a trace

Reliability of witness

Write an introduction for your portfolio. Who you are and what your portfolio will contain

Hand in 17/09/10



D8 evaluate their findings, including aspects of probability.

M8 justify the conclusions drawn in the report.

P8 report on a chemical, physical and biological forensic examination

Produce a case file of the investigation. This will need to include

A description of your crime scene examination A description of analysis Results from your investigation Conclusions from your report

You will need to submit everything from your crime scene and laboratory analysis documentation as part of your case file.

Give evidence in the mock court room explaining your role in the criminal investigation

You will need to give clear and logical justification for the conclusions that you have drawn from the evidence you have collected and analysed. In doing so you must

Support your conclusion with evidence and reasoning comment on the relevance of each piece of evidence to the

case in your report consider whether evidence may be circumstantial and

alternative motives behind the evidence

Evaluate your investigation in terms of precision, techniques and accuracy

Discuss the strengths and weaknesses of your results and conclusions

Discuss your conclusions in terms of possible, probable, likely

2

P1 carry out a forensic examination of a simulated crime scene using appropriate methods to gather biological, physical and chemical

M1 Describe the procedures used to gather evidence from a simulated crime scene

Practical – processing a crime scene and collecting evidence

Main points

Note-taking Sketching Photographing

Complete photography worksheet (M1, D1)

3 +4

P1 carry out a forensic examination of a simulated crime scene using appropriate methods to gather biological, physical and chemical M1 Describe the procedures used to gather evidence from a simulated crime scene

Practical – processing a crime scene and collecting evidence

Main points

Searching for evidence Targeting and recovery Packaging and labelling

4, 5, 6,7

P1 carry out a forensic examination of a simulated crime scene using appropriate methods to gather biological, physical and chemical

M1 Describe the procedures used to gather evidence from a simulated crime scene

D1 Justify the procedures used to gather evidence from a simulated crime scene

Lesson 4-5

Practical – independently process and collect evidence from a crime scene.

You receive a call from your chief inspector regarding a crime that has occurred. You rush to the crime scene to find a young caucasian male with a single bullet wound to his head. You are in charge of discovering all evidence to find out whether it was murder or suicide

Tool marks, blood, hair, fingerprints, fibre, saliva, bullet casing, gun powder, drugs

Learner observation sheet to be completed

Portfolio – complete your portfolio of how to process a crime scene

Lesson 6-7

Write up – How to process a crime scene for the portfolio using success criteria from student sheets

827/09/11

P2 Outline the main techniques used to analyse chemical evidence

M2 Explain the main techniques used to analyse chemical evidence

D2 Evaluate the techniques used to analyse chemical evidence

Practical – Chromatography techniques in forensic science

Paper chromatography and TLC

Procedure sheet needs to be completed as well as a brief description of how it


works

903/10/11




Practical – Colorimetry as a chemical analysis technique

Procedure sheet needs to be completed as well as a brief description of how it works

1004/10/11




Fingerprint chemical enhancement

Practical – Different methods of finding fingerprint

Iodine

Ninhydrin

Crystal violet

Procedure sheet needs to be completed as well as a brief description of how it works

Produce a document for your portfolio showing the four different types of fingerprints.

You must show on the document how forensic scientists match prints

Hand in 13/10/10

11, 1210/10/11




Practical – chemical presumptive tests of body fluids

Blood analysis

Saliva testing

Urine testing

Write up – use of presumptive tests in forensic science

1311/10/11




Research and describe how forensic scientists use the following procedures

Spectrometry

UV spectroscopy Infrared spectroscopy Mass Spectrometry

Ensure portfolio of chemical evidence is complete

Hand in 15/10/10

14,1517/10/1118/10/11

P4 Outline the main techniques used to analyse physical evidence

M4 Explain the main techniques used to analyse physical evidence

D4 Evaluate the techniques used to

Introduction to Ballistics

Practical – observation of bullet casings

Research and explain how forensic


analyse chemical evidence scientists use the following

Microstamping Discharge residue Wound patterns trajectory

16, 1731/10/11

P6 Outline the main techniques used to analyse biological evidence

M6 Explain the main techniques used to analyse biological evidence

D6 Evaluate the techniques used to analyse biological evidence




Practical – hair and fibre identification and analysis

Produce a table to look at advantages and disadvantages of different methods of analysis in forensic science. It should include uses, pros, cons, alternatives.

You should also have a minimum of 8 methods

Hand in 12/11/10

1801/11/11




Document examination

Practical – Handwriting analysis

Research what led to Harold Shipman conviction – hint old typewriter

197/11/11




Practical - blood typing and DNA profiling

20

14/11/11




Fingerprint patterns

Bones and skeleton physiology

21-2814/11/11 – 05/12/11

P3,5,7 Carry out practical work used to analyse evidence gathered from a simulated crime scene

M3,5,7 Present valid conclusions drawn from the analysis of evidence gathered from a simulated crime scene

D3,5,7 Justify the choice of

These next sessions are where you will complete your own forensic investigation. It is vital you attend each one. If you know you are going to miss a session please could you ask permission

Deadline for the assignment: 05/12/11


techniques used to analyse the chemical evidence gathered

P8 Report on a chemical, physical and biological forensic examination

M8 Justify the conclusions drawn in the report

D4 evaluate their findings, including aspects of probability

lesson 1 and 2

processing crime scene

Lesson 3

Plan how to analyse evidence the evidence

Lesson 4-5

Analysis of the evidence

Lesson 6-7

Draw conclusions and completion of their report and assignment


Assignment 1 Student Tick List

Distinction

In your portfolio you will need to produce a table that discusses the advantages and disadvantages of different methods in forensic science. This should cover all of the content in M2. Evaluated the methods and techniques that you have used in your investigation. Include alternative techniques that you could also have used

Support your conclusions with evidence and reasoning.

Ensure that your report is precise and concise

Discuss your conclusions in terms of possible, probable, likely

Evaluate your investigation in terms of precision, techniques and accuracy

Present your results in a suitable format

Draw conclusions from your results


D1 justify the procedures used to gather evidence from a crime scene and show how a systematic application of procedures can minimise the risk of missing forensic evidence

D3 draw valid conclusions based upon the evidence from their forensic examination of a crime scene and present the results appropriatelyD4 evaluate how the information could be communicated more clearly, including aspects of probability.

D2 evaluate the techniques used in the analysis of forensic evidence and identify the types of evidence or circumstances in which each might be appropriate


In your portfolio you must include pictures and diagrams to help you explain the different methods used in the analysis of forensic evidence. You will need to ensure this covers the following

Spectrometry Chromatography Toxicology Finger printing DNA sequencing and blood grouping Microscopic evidence Photography Ballistics Audiometry Anthropology


Procedure for TLC of lipstick

1. Prepare the solvent for the chromatographic analysis. The solvent is a mixture designed to aid the separation of dye components used in lipsticks. Prepare by mixing the following solvents:

15ml isoamyl alcohol 15 ml acetone 7.5 ml deionised water 15 drops of 6M ammonium hydroxide

2. Place about 15ml of the elution solvent in a beaker and cover.

3 Take a small sample of each of the samples provided and place in the sample bottle provided. Add about 5-8 drops of petroleum ether to each sample. Use a glass rod to “pound” the lipstick sample so that as much of the lipstick dye goes into solution. Add a further 3-4 drops of the solvent prepared in step 1, above, and shake the sample bottle to ensure that the components in the lipstick are extracted. Leave for about 10 minutes.

4. Draw a faint line about 1 cm from the bottom of the TLC plate with a pencil. This is the baseline. Take care not to disturb the silica gel surface. At the top of the plate write 1,2,3,4…. to indicate your sample number.

5. Using a TLC spotter, spot each lipstick sample from the coloured lipstick solutions on the TLC plate. You will need to spot several times, ensuring to let the spot dry between applications (use hairdryer provided).

6. Place your TLC plate in the solvent in the beaker, ensuring that the solvent is below the baseline.

While waiting for the TLC plates:

7 Examine the evidence provided – a cigarette with a lipstick smear. Determine, by colour-matching the three most likely matches to the lipstick smear “evidence”. Use the stereomicroscope to examine the samples and the UV light to examine for any fluorescent components.

8 Using a clean scissors or scalpel, remove the lipstick smear from the clothing. Keep the top layer containing the smear only. Following the same procedure as above (Step 3) dissolve the lipstick sample in approximately 5 drops of petroleum ether followed by 2-3 drops of the elution solvent.

9. Remove the remaining cloth and spot the solvent from the lipstick on a TLC plate along with the most likely matches. The “cloth sample” should be spotted at least five times – taking care to ensure that the spot remains small. A hairdryer can be used to dry the sample between spotting. This should be done in the fume hood.

10. When the solvent front is about 1 cm from the top of the TLC plates, remove the plate from the beaker and immediately mark the solvent front with a pencil. The TLC plate can be dried completely using a hairdryer in the fume hood.


Results

Compare the spots from the unknown lipstick sample with the four known lipsticks. At the centre of each spot that you observe, place a dot with a pencil. There may be more than one spot for a

given sample. Some dyes may be visible only under UV light. Calculate the Rf value for each spot, note the colour of each spot, and tabulate the results.

Rf = Distance travelled by a spot (cm)

Distance travelled by the solvent front (cm)

Questions

· Do any of the lipsticks from the three teachers match the lipstick found? Justify your reasoning.

· What type of dyes are generally used in cosmetics such as lipsticks?

The work that you have completed today need to be compiled into your portfolio of techniques. Remember if you want to achieve the Merits it is up to YOU to do individual research on the other types of chromatography and include these in your portfolio

Good luck


Chemical enhancement of fingerprints

Black powder

Developing the print:

Procedure

1. Dip the brush in the powder and lightly dust the microscope slide containing the print. Use only a very small amount of powder. Be gentle when dusting the slide. A swirling motion with the brush works well.

2. To lift the print from the slide to the index card, unroll about 5Ó to 6Ó of clear packing tape and place the end to the right of the thumb print on the slide and allow the tape to cover the whole print. Slide a thumb over the tape and smooth it down over the print to force out all air bubbles.

3. The print can be removed by pulling up on the roll end of the tape and then placing it on the blank index card in the same manner as the tape was placed over the latent print. Make sure the tape is secure. Cut the tape from the roll.

4. Determine the pattern and identity of the print and record on the data sheet.

Ninhydrin


When using ninhydrin, always wear gloves!

A. Prepare the "sandwich" papers by cutting two squares of white paper, each about 6-7 cm on a side. Label each paper, along the edge, using pencil, with the word "sandwich."

B. Working over a sink, spray these two papers with the ninhydrin solution until they are soaked. Hold the papers and allow to air dry.

C. Place the evidence (paper with the print) between the two sandwich papers, and place flat on the cloth

D. Iron the "sandwich," with the iron on the highest setting, for about 45 seconds, moving the iron back and forth the entire time. Watch the papers carefully to make sure they do not burn.

E. Remove the evidence paper and examine the print.


Superglue fumes


1. Make a small cup of aluminum foil. Put seven to ten drops of superglue in this cup.

2. Place the cup in the fuming chamber (this can be an old aquarium, turned upside-down, a lidded box lined in foil, or a chamber made for the purpose). For fastest results, put the cup of foil on a coffee cup warmer or candle warmer. Also, put a cup of warm water in the chamber

3. Put the foil evidence in the chamber, being sure to not let the evidence touch the superglue. (If possible, hang the evidence in the chamber.) Close the chamber and wait about 20 minutes (or 24 hours if the glue is not heated).

Crystal violet

Developing the prints:

Wearing gloves, dip the masking tape into the tray of crystal violet solution and let sit for two to three minutes. Remove the tape, and immediately rinse with tap water. Place the tape (sticky side up) on a paper towel to dry.

Iodine fumes


When using iodine, avoid inhaling fumes! Keep the jar closed as much as possible and do not inhale the iodine fumes. Iodine sublimates (turns from solid to gas) very quickly and produces toxic fumes.

1. Wear gloves to carry out the following steps.

2. Place a few (5 to 8) crystals of iodine in a small jar.

3. Open the jar containing the iodine crystals and quickly put the paper into the jar so that it is not in direct contact with the crystals. Replace the lid and allow the print to absorb the iodine vapor for about 5 to 10 minutes or until the print is visible.

4. Once you can see the developed print, use forceps to remove the paper from the jar. Be sure to quickly replace the lid on the jar to avoid inhaling the fumes. Leave the crystals in the jar

THIS MUST BE DONE IN A FUME CUPBOARD!!


Forensic Photography

Describe below how to correctly photograph evidence at a crime scene

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

In the boxes below find 4 different pieces of equipment that can be used in forensic photography. Explain how they work and use pictures to help you

Why is it important that evidence is photographed?

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


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