AC 1.3 – Writing Frames
Physical evidence:
One type of evidence is physical evidence. This is evidence that is visible at the
crime scene and can be collected and examined. Locard stated that ‘every
contact leaves a trace’, meaning that material from a crime scene will be present
on an offender and material from the offender will be present at the crime scene.
When collecting this type of evidence, SOCOs need to be extremely careful not to
cause contamination as this would make the evidence inadmissible. To try to
prevent contamination, they wear protective clothing such as boot covers, gloves
and bunny suits. Types of physical evidence include bodily fluids and tissues
(such as blood, semen, skin flakes and saliva), trace evidence (such as fibres,
paint, insects and soil) and impression evidence (such as shoeprints, tyre marks
and bite marks).
The first step involved in processing blood is collection. If the blood is wet,
SOCOs at the crime scene will collect it using a gauze or sterile cotton pad and
transfer it to a fridge or freezer. It will then be taken to the laboratory and stored
at room temperature to fully dry. The sample will then be analysed by forensic
scientists at the lab within 24 hours to try and extract any DNA samples that can
be compared to DNA already stored on the database. If the sample is already dry
at the scene, SOCOs will either scrape it off the surface and transfer it to a paper
envelope for storage or if it is on a small object such as clothing the whole item
can be transferred into a sterile bag for storage. These samples will then be sent
to the lab and analysed by forensic scientists in the same way as wet blood. A
case in which blood samples were able to identify a killer was in the case of
Stephen Lawrence. Nearly 13 years after Lawrenc’s murder, prior evidence was
re-examined and a blood splatter was found on the collar of suspect Dobson’s
jacket. This evidence was analysed and found to match Stephen Lawrence’s
DNA. Therefore, allowing Dobson to be linked to his murder and be convicted.
One example of trace evidence is fibres. These are collected from the crime
scene by SOCOs and trace evidence experts using tweezers and gloves to
carefully transfer the fibres into paper which can then be sealed in a bag for
storage. The fibres are then sent to a lab for analysis by forensic scientists where
they can discover important information such as specific dyes used on the item
which could link them to a manufacturer. This information can help them to link
the fibres to a suspect. Fibres can also be found on a suspect which can then be
processed in the same way to link them to a crime. For example, in the Damilola
Taylor case, clothing fibres found on the bottom of Danny Preddie’s shoe
amongst Damilola’s blood were analysed and revealed that the fibres matched
the ones from the jumper Damilola was wearing on the day he was murdered.
Therefore, strongly linking Preddie to the crime.
Testimonial evidence:
One type of evidence is testimonial evidence. This can be a written or spoken
statement that is given in court. Rules of disclosure mean that prior to attending
court, the prosecution and defence must disclose any written statements and
witnesses that they will be using during the trial. The evidence will be given in
court from the witness box where the opposing side can cross-examine the
Physical evidence:
One type of evidence is physical evidence. This is evidence that is visible at the
crime scene and can be collected and examined. Locard stated that ‘every
contact leaves a trace’, meaning that material from a crime scene will be present
on an offender and material from the offender will be present at the crime scene.
When collecting this type of evidence, SOCOs need to be extremely careful not to
cause contamination as this would make the evidence inadmissible. To try to
prevent contamination, they wear protective clothing such as boot covers, gloves
and bunny suits. Types of physical evidence include bodily fluids and tissues
(such as blood, semen, skin flakes and saliva), trace evidence (such as fibres,
paint, insects and soil) and impression evidence (such as shoeprints, tyre marks
and bite marks).
The first step involved in processing blood is collection. If the blood is wet,
SOCOs at the crime scene will collect it using a gauze or sterile cotton pad and
transfer it to a fridge or freezer. It will then be taken to the laboratory and stored
at room temperature to fully dry. The sample will then be analysed by forensic
scientists at the lab within 24 hours to try and extract any DNA samples that can
be compared to DNA already stored on the database. If the sample is already dry
at the scene, SOCOs will either scrape it off the surface and transfer it to a paper
envelope for storage or if it is on a small object such as clothing the whole item
can be transferred into a sterile bag for storage. These samples will then be sent
to the lab and analysed by forensic scientists in the same way as wet blood. A
case in which blood samples were able to identify a killer was in the case of
Stephen Lawrence. Nearly 13 years after Lawrenc’s murder, prior evidence was
re-examined and a blood splatter was found on the collar of suspect Dobson’s
jacket. This evidence was analysed and found to match Stephen Lawrence’s
DNA. Therefore, allowing Dobson to be linked to his murder and be convicted.
One example of trace evidence is fibres. These are collected from the crime
scene by SOCOs and trace evidence experts using tweezers and gloves to
carefully transfer the fibres into paper which can then be sealed in a bag for
storage. The fibres are then sent to a lab for analysis by forensic scientists where
they can discover important information such as specific dyes used on the item
which could link them to a manufacturer. This information can help them to link
the fibres to a suspect. Fibres can also be found on a suspect which can then be
processed in the same way to link them to a crime. For example, in the Damilola
Taylor case, clothing fibres found on the bottom of Danny Preddie’s shoe
amongst Damilola’s blood were analysed and revealed that the fibres matched
the ones from the jumper Damilola was wearing on the day he was murdered.
Therefore, strongly linking Preddie to the crime.
Testimonial evidence:
One type of evidence is testimonial evidence. This can be a written or spoken
statement that is given in court. Rules of disclosure mean that prior to attending
court, the prosecution and defence must disclose any written statements and
witnesses that they will be using during the trial. The evidence will be given in
court from the witness box where the opposing side can cross-examine the
