Please enable JavaScript.
Coggle requires JavaScript to display documents.
Assess the usefulness of investigative techniques in criminal…
Assess the usefulness of investigative techniques in criminal investigations overview sheet
Intelligence database
The police national Database contains intelligence about suspected criminal activity as well as the data on the PNC. holds over 3.5 billion searchable records and is itself made up of 220 linked database
The police national computer - contains several databases
it stores details of over 12 million people's arrests, convictions, and police cautions, with links to biometric databases for fingerprints and the national DNA database.
crimint and the gangs matrix- crimint holds information on criminals, suspects and protestors.
International databases - uk police can also access databases that share info between police forces in different countries. eg INTERPOL on child sexual exploitation
forensic techniques
Range of forensic experts and specialist but most often forensic techniques involve investigators recovering evidence from a crime scene and submitting it.
Forensic evidence can include: blood, semen, skin flakes, and hair. along with fingerprints, shoeprints, weapons, fibres and threads from clothing.
Evidence is collected from the crime scene to be analysed to reach a conclusion in which they can then provide a court testimony about the findings. essential access to the crime scene is controlled and that investigators wear appropriate protective clothing to avoid contamination.
Once collected the evidence is examined by forensic specialists and the result is shared with the police.
DNA evidence - DNA is found in almost every cell of the human body; however, each person's DNA is unique- except monozygotic twins. Meaning the offender is easily identifiable though DNA sampling. consequently,In recent years, highly sensitive equipment have been developed for the extraction, leading to rapid analysis of minute quantities of DNA samples. This has made DNA profiling most important + revolutionary solving serious crime
Refers to any type of science that is used in the legal field or justice system to support and uphold the law.
Alec Jefferys ( scientist) invented DNA profiling in 1985, where it was first used to investigate the rape and murder of 2 girls in Leicestershire in 1983 and 1986
Case study - Collin Pitchford + colette Adam Case
Trustworthy in tracing an individual and ability to build a picture of events, as well as give objective findings.
Revolutionary scientific developments are expanding and are now cheaper.
Can be found in almost every cell in the human body, this is effective in providing high reliability as everyone's is unique
Contamination risk high, might occur at crime scene or lab, and lead to miscarriage of justice, raised police keeping DNA of so many people were a danger to civil liberties = December 2008 equality human rights act rules DNA could not be stored for those found innocent + 2012 protection act
Surveillance techniques
CCTV is used by the police in criminal investigations as it can give 24 hour coverage of a location, prove a visual record of a crime and help to identify a perpetrator. CCTV includes images and videos from the public and private cameras.
FACT - each person is captured up to 30 times a day on CCTV.
Major investigation technique where around 1.5 million cameras are in airports, stations, cities, big stores within the UK.
Case study - London Riots + James Bolger case
Covert surveillance is planned by the police and those being monitored are not aware they are being watched. information can be gained under cover, BUT due to possible infringement of civil liberties, there are strict rules on Covert Human intelligence sources.
Covert servilance is planned and can take several forms, these can include tracking, intercepting mail, static serveilance eg unmarked police cars, undercover officers
Case study - Rachel Nickell Case
CCTV Usefull? useful in providing a visual record of the crime, by identifying the perpetrator and showing the time and conditions of the crime. This can further then be released to the media to support the investigation, for example, witness appeals. Proven useful to gain convictions against major drug cartels, to gather high quality info and intelligence. Can be planned and target a specific person closely, while following strict rules for preventing unwarranted intrusions into personal lives
Arguably not useful? often fixed so cannot follow a target around, as well as criminals aware of the locations of cameras so may work to avoid them. Poor quality images and lack of sound may hinder its essentialness as well as CCTV is not present in remote areas or private residence,= not useful for a wide range of crimes. Covert surveillance breaches the HRS 1998 " right to private and family life", + potentially become a case of entrapment
In the case of Collin stagg, wrongfully convicted for the 'Wimbledon common' murder of Rachel nickels in 1992, police used an undercover female officer
Interviewing techniques ( ewt)
EWT are accounts given by a witness to a crime and are generally accepted as accurate accounts of crime. Police can interview experts and specialists for information and advice on different aspects of their investigation.
Devlin Committee found that juries will convict in 74% of cases where line up ID was the only prosecution evidence. However, the innocent project (USA) has found that 239 wrongful convictions that were overturned due to DNA evidenc, 70% were convicted due to EWT, including 15 death row cases
Memory acquisition is vital in the accuracy of the EWT, there are several factors which will influence this, one being:
duration of time exposed the more likely you are to remember-
time of day - kuehn (1974) found EWT was the best in full daylight or at night when paid closer attention due to conditions.
time distortion - witnesses may over estimate how emotional or dramatic events are
violent detraction- witnesses recall violent events less accurately, probably because witnessing violence produces high anxiety levels that impair memory.
weapon focus - when a weapon is used the EW is likely to focus on the weapon and prevented from forming detailed memory of the offender
Memory retention - retention refers to the storing of important info in memory. The 2 main factors which will affect memory retention are time and post event discussion.
time : memory traces in the brain fade overtime and info is lost. However, there is one exception, memory for faces does not fade overtime, so a witness who can't remember details of the crime may still be able to identify an offender.
discussion of event: often discuss the event meaning it adds more detailed recall but also reduces accuracy as one witness who saw a knife may influence the opinion of another witness who saw no murder weapon. This means that officers will attempt to separate witnesses when they get to the scene .
When recalling the events - misleading questions and information can affect a witness's memory and produce inaccuracies, as research by Loftus and palmer shows, show people a film of a car crash and ask them specific question changing the verb to analyse how their answers differ.
Case study - libby squire
Police can ask questions for clarification and to develop their lines of inquiry into the crime, using forensic specialist knowledge: pathologists can analyse the likely cause of death in homicide cases, based on the post mortum. These questions can test the reliability of the ew
Geographical profiling
Method of Criminal investigation that examines the locations of connected series of crimes to determine the most likely area of offender residence. It aids in understanding spacial behaviour of an offender and focuses the investigation on a smaller area. Geographical profiling works to examine the offenders patterns of crimes to determine if they are a 'marauder' = operates in their home base or a commuter = likely to travelled a distance away from their usual residence
1993, canter and Larkin argued if you draw a circle around the crime scenes, the killer is 85% likely to live there. This is the buffer zone. = offender will avoid offending too close to home in case they are recognised , for example an offender wouldn't burgle a neighbour as they have a high risk of being caught.
However, the least effort principle refers to when an offender is given 2 identically attractive targets, they will chose the one nearest home.
Case study - John Duffy
Although geographical profiling has had some success in predicting where to find the offender in a range of crimes including rape, arson, burglary, it is required that the profiler must be sure the crimes were committed by the same person and sure that they haven't missed crimes that lie outside the circle point. Canters rule assumes offenders will follow one rule or the other. Relies on accurate data, if not , it will affect the map
Typological profiling
A typology is a classification system, + typological profiling aims to classify offenders into different types with different characteristics based on how they behave at the crime scene
Divides crimes into 2 types: organised and disorganised.
Helps police identify likely suspects and narrow down their search, it can also used to predict their likely future of behaviour.
clinical profiling
psychiatrists who use their professional experience to get inside the mind of the offender. rather than using typologies.
Best known clinical profiler is Paul Britton. who immerses himself into the offenders thoughts and feelings when committing a crime.
Based on the profilers clinical experience of working with convicted offenders, which may be untypical or limited. can produce unsupported speculations about the offenders characteristics and motivations. This can side track an investigation and can result in wrongful convictions if incorrect