AC1.3 Explain how evidence is processed
There are two types of evidence collected in criminal investigations: physical evidence and
testimonial evidence. Physical evidence is real evidence that consists of tangible pieces
such as fingerprints, hair and bloodstains. Testimonial evidence is a statement or the spoken
words from the defendant, a victim or a witness. These can also take the form of eyewitness
accounts of victim statements.
Physical Evidence
Physical evidence is an important part of court cases and prosecutions, this type of evidence
is used frequently in criminal cases. This could be due to Locard’s Exchange Principle, a
forensic scientist, which suggests that every time someone enters an environment,
something is added to and removed from it. In other words, every contact leaves a trace.
This includes contact between individuals as well as between a person and a physical
environment. Scenes of crime officers (SOCO) always work on the principle that physical
evidence has been left behind at every scene. However, this exchange can cause issues in
criminal cases.For instance, Barry George was wrongly convicted of murder and sentence to
life imprisonment in 2001. This is because gunshot residue of one ten thousandth of a
centimetre was found in his jacket pocket. This gunshot residue was said to have come from
the police firearms that were taken into his flat during the search and ended up inside his
pocket which resulted in a miscarriage of justice.
Physical evidence can also help in piecing a timeline in murder cases to work out who the
perptrator is. Joanna Yeates went missing on the 17th December 2010 and was found
murdered a few days later on christmas day. On the night she went missing there was CCTV
footage that revealed she went to the shop and came home with pizza. Her post mortem
results showed she had been strangled but there was no pizza in her system despite buying
it from the shop. This helps majorly with piecing the timeline. During the time of the murder it
was snowing so most evidence couldn’t be preserved when the body was found outside on
the side of the road. Joanna suffered 43 injuries and her t-shirt has been pulled up above
her breasts. A sample of a suspect's DNA was found on her chest which led to the
conviction of her neighbour Vincent Tabak.
Physical evidence can also have its negatives. For example, physical evidence was used to
convict Adam Scott who was wrongly convicted of rape in 2011 when in fact Adam was
hundreds of miles away from the crime scene. Due to a mix up in a forensic lab that had a
sample of Adams DNA from a spitting incident prior. The tray used for his DNA was reused
for the rape case and the tray contained traces of Adams DNA which applied that he was
guilty. This led to an innocent man being held in police custody for months while the rapist
was still on the loose with police not investigating.
When dealing with an outdoor crime scene physical evidence can become problematic and
can become inadmissible evidence in court. This is because weather conditions may destroy
and contaminate evidence leaving it useless. Harsh weather such as wind or rain can make
evidence be lost or destroyed.
There are two types of evidence collected in criminal investigations: physical evidence and
testimonial evidence. Physical evidence is real evidence that consists of tangible pieces
such as fingerprints, hair and bloodstains. Testimonial evidence is a statement or the spoken
words from the defendant, a victim or a witness. These can also take the form of eyewitness
accounts of victim statements.
Physical Evidence
Physical evidence is an important part of court cases and prosecutions, this type of evidence
is used frequently in criminal cases. This could be due to Locard’s Exchange Principle, a
forensic scientist, which suggests that every time someone enters an environment,
something is added to and removed from it. In other words, every contact leaves a trace.
This includes contact between individuals as well as between a person and a physical
environment. Scenes of crime officers (SOCO) always work on the principle that physical
evidence has been left behind at every scene. However, this exchange can cause issues in
criminal cases.For instance, Barry George was wrongly convicted of murder and sentence to
life imprisonment in 2001. This is because gunshot residue of one ten thousandth of a
centimetre was found in his jacket pocket. This gunshot residue was said to have come from
the police firearms that were taken into his flat during the search and ended up inside his
pocket which resulted in a miscarriage of justice.
Physical evidence can also help in piecing a timeline in murder cases to work out who the
perptrator is. Joanna Yeates went missing on the 17th December 2010 and was found
murdered a few days later on christmas day. On the night she went missing there was CCTV
footage that revealed she went to the shop and came home with pizza. Her post mortem
results showed she had been strangled but there was no pizza in her system despite buying
it from the shop. This helps majorly with piecing the timeline. During the time of the murder it
was snowing so most evidence couldn’t be preserved when the body was found outside on
the side of the road. Joanna suffered 43 injuries and her t-shirt has been pulled up above
her breasts. A sample of a suspect's DNA was found on her chest which led to the
conviction of her neighbour Vincent Tabak.
Physical evidence can also have its negatives. For example, physical evidence was used to
convict Adam Scott who was wrongly convicted of rape in 2011 when in fact Adam was
hundreds of miles away from the crime scene. Due to a mix up in a forensic lab that had a
sample of Adams DNA from a spitting incident prior. The tray used for his DNA was reused
for the rape case and the tray contained traces of Adams DNA which applied that he was
guilty. This led to an innocent man being held in police custody for months while the rapist
was still on the loose with police not investigating.
When dealing with an outdoor crime scene physical evidence can become problematic and
can become inadmissible evidence in court. This is because weather conditions may destroy
and contaminate evidence leaving it useless. Harsh weather such as wind or rain can make
evidence be lost or destroyed.
