AC2.4 - Assess the key influences affecting the outcomes of criminal cases
Reliability of evidence
- Evidence is very important in criminal cases - physical and testimonial
- There has to be sufficient evidence before the CPS decide to charge a suspect
- Prosecution presents their evidence, the defence cross examines and presents their
own evidence.
- By the end of the trial the prosecution has to convince the jury/magistrates that the
defendant is guilty beyond a reasonable doubt otherwise he must be acquitted.
Case Example - Colin Stagg
- Rachel Nickell was murdered in Wimbledon Common, with the only witness being
her son
- The son, Alex, managed to give a description of the killer
- Criminal profiler, Paul Britton, was hired to help the investigation
- Colin Stagg was arrested for the murder but there was no evidence
- An undercover female police officer was used to try and trap Stagg into confessing
- He did not confess to the officer
- Robert Napper refused to give DNA evidence to the police
- Green Chain - series of rapes by Robert Napper
- Britton did not link the Green Chain
- Napper murdered a young mum and a daughter in their own home
- A fingerprint was found at the scene
- The case against Colin Stagg was thrown out of court
- Paint found in Alex’s hair patched the paint of Napper’s toolbox
Case Example - David Butler
- Mr Butler was accused of murdering a woman, Anne Marie Foy, in 2005.
- His DNA sample was on record after he had given it to them as part of an
investigation into a burglary. The DNA sample was only a partial match, of poor
quality, and experts at the time said they could neither say that he was guilty nor rule
him out.
- He spent eight months in prison, on remand, facing murder charges. The case
eventually went to trial and Mr Butler was acquitted and finally released, and nobody
was ever charged with the murder.
Case Example - Anthony Diedrick
- Anthony Diedrick strangled a 27-year-old doctor who rejected him after their
relationship ended.
- Four years later he was charged with murder after forensic scientists uncovered
three tiny blood specks belonging to Diedrick on the collar of her pink T-shirt.
Case Example - Sally Clarke
, - Sally Clarke was wrongly convicted of murdering her two baby sons. They had in fact
died from sudden infant death syndrome, but a professor told the jury that this was
very unlikely to be true based on probability. It was later found his research was
incorrect.
- This demonstrates how evidence that is incorrect can lead to miscarriages of justice.
Case Example - Stephen Downing
- Wendy Sewell was attacked, in Bakewell Cemetery, at lunchtime on 12 September
1973. A witness, Charles Carman, saw her enter the cemetery at about 12:50 pm.
She was beaten around the head with the handle of a pickaxe and sexually assaulted
- Stephen Downing, who worked at the cemetery, was the person who found the body
and called the police.
- A forensic scientist Norman Lee, gave evidence that the blood found on the accused
could only have been present if he had been responsible for the assault.
- This evidence led to him being found guilty
- He remained in prison for 27 years before his conviction was quashed
Witnesses
- Both prosecution and defence teams are entitled to call witnesses to give testimonial
evidence. This is given in person, unless they are vulnerable or intimidated witnesses
- Witnesses can be called by both sides to give evidence - this is called examination-
in-chief. There is also an opportunity to cross examine.
- Jurors and magistrates can give whatever weight they choose to the evidence of
witnesses. The quality of their evidence can determine the outcome of the trial eg.
Have they been shown to lie, is there evidence inconsistent, unreliable or not
credible.
- Racial and gender stereotypes held by jurors may influence how likely the jury are to
believe a witness testimony
- In addition to this, Brodsky et al found that juror’s view of the witnesses knowledge
and factors like likeability influenced them in deciding whether to believe their
evidence.
Case Example - Ronald Cotton
- In July 1984, a man broke into Jennifer Thompson-Cannino’s apartment and sexually
assaulted her.
- Ronald Cotton was arrested and charged based on the basis of Jennifer choosing
Cotton out of a photo lineup
- On June 30, 1995, Cotton was officially cleared of all charges and released from
prison. In July 1995, the governor of North Carolina officially pardoned Cotton. Cotton
had served 10.5 years in prison.
Experts
Reliability of evidence
- Evidence is very important in criminal cases - physical and testimonial
- There has to be sufficient evidence before the CPS decide to charge a suspect
- Prosecution presents their evidence, the defence cross examines and presents their
own evidence.
- By the end of the trial the prosecution has to convince the jury/magistrates that the
defendant is guilty beyond a reasonable doubt otherwise he must be acquitted.
Case Example - Colin Stagg
- Rachel Nickell was murdered in Wimbledon Common, with the only witness being
her son
- The son, Alex, managed to give a description of the killer
- Criminal profiler, Paul Britton, was hired to help the investigation
- Colin Stagg was arrested for the murder but there was no evidence
- An undercover female police officer was used to try and trap Stagg into confessing
- He did not confess to the officer
- Robert Napper refused to give DNA evidence to the police
- Green Chain - series of rapes by Robert Napper
- Britton did not link the Green Chain
- Napper murdered a young mum and a daughter in their own home
- A fingerprint was found at the scene
- The case against Colin Stagg was thrown out of court
- Paint found in Alex’s hair patched the paint of Napper’s toolbox
Case Example - David Butler
- Mr Butler was accused of murdering a woman, Anne Marie Foy, in 2005.
- His DNA sample was on record after he had given it to them as part of an
investigation into a burglary. The DNA sample was only a partial match, of poor
quality, and experts at the time said they could neither say that he was guilty nor rule
him out.
- He spent eight months in prison, on remand, facing murder charges. The case
eventually went to trial and Mr Butler was acquitted and finally released, and nobody
was ever charged with the murder.
Case Example - Anthony Diedrick
- Anthony Diedrick strangled a 27-year-old doctor who rejected him after their
relationship ended.
- Four years later he was charged with murder after forensic scientists uncovered
three tiny blood specks belonging to Diedrick on the collar of her pink T-shirt.
Case Example - Sally Clarke
, - Sally Clarke was wrongly convicted of murdering her two baby sons. They had in fact
died from sudden infant death syndrome, but a professor told the jury that this was
very unlikely to be true based on probability. It was later found his research was
incorrect.
- This demonstrates how evidence that is incorrect can lead to miscarriages of justice.
Case Example - Stephen Downing
- Wendy Sewell was attacked, in Bakewell Cemetery, at lunchtime on 12 September
1973. A witness, Charles Carman, saw her enter the cemetery at about 12:50 pm.
She was beaten around the head with the handle of a pickaxe and sexually assaulted
- Stephen Downing, who worked at the cemetery, was the person who found the body
and called the police.
- A forensic scientist Norman Lee, gave evidence that the blood found on the accused
could only have been present if he had been responsible for the assault.
- This evidence led to him being found guilty
- He remained in prison for 27 years before his conviction was quashed
Witnesses
- Both prosecution and defence teams are entitled to call witnesses to give testimonial
evidence. This is given in person, unless they are vulnerable or intimidated witnesses
- Witnesses can be called by both sides to give evidence - this is called examination-
in-chief. There is also an opportunity to cross examine.
- Jurors and magistrates can give whatever weight they choose to the evidence of
witnesses. The quality of their evidence can determine the outcome of the trial eg.
Have they been shown to lie, is there evidence inconsistent, unreliable or not
credible.
- Racial and gender stereotypes held by jurors may influence how likely the jury are to
believe a witness testimony
- In addition to this, Brodsky et al found that juror’s view of the witnesses knowledge
and factors like likeability influenced them in deciding whether to believe their
evidence.
Case Example - Ronald Cotton
- In July 1984, a man broke into Jennifer Thompson-Cannino’s apartment and sexually
assaulted her.
- Ronald Cotton was arrested and charged based on the basis of Jennifer choosing
Cotton out of a photo lineup
- On June 30, 1995, Cotton was officially cleared of all charges and released from
prison. In July 1995, the governor of North Carolina officially pardoned Cotton. Cotton
had served 10.5 years in prison.
Experts
