Crime Scene Investigation Guidelines

Questions to ask leading officer

Who reported the crime?

What is the nature of the crime?

Where there any witnesses, any CCTV, has there been any initial statements?

Is there any sign of how the suspect got in or out?

Has there been any similar incidents in the area recently?

What was the weather like at the time of the incident?

Who has already entered the scene?

Can you describe the scene as it was first found?

Are there any hazards or dangers?

Is the scene secure and cordoned off?

What are our designated entry and exit routes?

Sketching

Add evidence into the sketch:  

- Measure each items distance from 2 fixed points 

- Label each item numerically to match evidence log 

Add furniture to sketch 

- Use basic shapes

- Label each with letters 

Add directional marker (North) into sketch to orient the scene 

Label Sketch 

- Address 

- Date/Time

- Signature  

Modus Operandi

- Method of entry 

- Type of Crime 

- Tools used 

- Mention if unknown/undetermined

Crime Scene observations

- Written during preliminary walkthrough

- Scene Conditions (tidy, signs of struggle) 

- Weather Conditions (if outdoors or relevant) 

- Observed possible entry/exit points (doors/windows) and their condition 

- Any signs of tampering or entry 

Investigation Details

- People at scene 

- PPE

- Time of entry 

- Tasks carried out 

- Preliminary walkthrough - Record general observations here 

- Instructed by crime scene manager to observe specific room

- Placing evidence numbers 

- Completing sketch 

- Collecting evidence

- Time tasks are started and completed 

- Time of Departure 

Evidence details

 Type of evidence and where it was found 

- With URN 

- Any pre-processing required (blood tests) and their results

- Time and method of collection 

- Record handover to exhibits officer - time and person 

Final Contemporaneous notes details

- Cross out and sign all empty space

- Sign and date page 

Order of collecting evidence

• Evidence in common routes

• Trace evidence (fibres, hairs, glass fragments, soil)

• Biological samples (swabs)

• Suspected drugs if loose and/or hazardous

• Latent Prints

• Suspected drugs if stable and non hazardous

• Dangerous items

• Outdoor items

• More stable evidence

Kastle Meyer Test

 Fold a piece of filter paper into quarters 

- Rub the paper againts the stain

- Add 1-2 drops of ethanol 

- Add 1-2 drops kastle Meyer reagent, 

- Add 1-2 drops hydrogen peroxide 

- Bright pink is a positive result

Dusting for fingerprints

- Use Aluminium powder and Zeffer brush 

- Use a very small amount of powder

- Apply in a circular motion 

- Or use Black powder and pony hair brush 

- Use a very small amount of powder

- Apply in a vertical or horizontal motion 

- Lift with tape 

- Place on acetate sheet 

- With: Police force, Address, Date, Exhibit number (URN), Crime reference number, Directional arrow 

Taking a cast of a footprint

- Use 5 times the amount of water to plaster 

- Mix for 3-5 minutes to acheive the consistency of heavy cream 

- Pour casting material just outside perimeter of impression, cover the entire print

- Allow the plaster to set for 20 - 30 minutes 

Taking a cast of a toolmark

- Load the Isomark Gun

- Apply a controlled layer of the casting material, covering to Toolmark completely 

- Leave the material to set 

ESLA lift

- Used on dry powdery footprints 

- Place foil black side down 

- Place earth plate down within 5cm of the film 

- Place the electrode on the foil, with the negative electrodes in contact with the earth plate 

- Switch on the electrode 

- Use roller to elimate trapped air 

- Allow 10 seconds for the print to be lifted 

- Turn off ESLA 

- Leave for 30 seconds before dismantaling 

When to ask for an expert

Firearms/Ballistics Expert

Glass Fragmentation Pattern 

Toolmark Expert 

Bloodsplatter pattern expert

Labelling evidence

Label before you package

URN: HGS/1, HS/2 …

Crime Number 

Address

Signature

Date, time 

Clear and accurate item description 

Sealing evidence

Tape across all openings, signed across 

Polythene bags:

- Non Volatile 

- Secondary container for trace evidence 

Paper bags

- Dry clothing 

- Shoes

- Plant material

- Wet or stained items - breathability 

- Folded over twice  

Cardboard boxes 

- Heavy items 

- Weapons 

- Fragmented glass 

- Casts

- Secure all items with inserts or cable ties 

- Documentation 

- All gaps and edges sealed 

Plastic or glass containers 

- Unknown liquid samples 

- Unknown chemicals 

Swabs 

- Suspected blood 

- Placed in polyethlyne bag 

Beechams wrap 

- Trace evidence 

- Placed in polyethylene bag 

Faraday bag

- Electronic devices