Scenes of Crime Officer
Few people will have missed seeing a CSI at work on the TV. If not on the TV news dealing with a real crime it may be an episode of Frost! We even have our own TV show in America ‘CSI’, Crime Scene Investigation! The attention-grabbing image portrayed by the media is of a busy murder scene with CSI team in protective suits using the latest high-tech equipment and coloured lights! So, yes, we sometimes do that, when we have good reason, but remember what you see there is for entertainment with only fictional victims.
Rather than CSI, many UK police forces still prefer the traditional term SOCO, Scenes Of Crime Officer. Unlike the TV shows, most of our work is about quietly and diligently looking for evidence left on stolen cars or at scenes of burglary etc.
SOCOs learn to recover fingerprints and forensic evidence and how to photograph crime scenes and evidence. Later there may be other courses that specialise in areas such as fire investigation and a requirement to evidence maintained competency in the role.
SOCO tasks would include:
Preserving and protecting the crime scene so that evidence can be recovered and recorded without being lost, spoilt or destroyed.
Finding out what evidence is needed, deciding the best way to recover it and collecting it as required.
Recording the scene using photography and video.
Searching for evidence footprints and for marks left by tools or weapons.
Developing, recording and capturing fingerprint evidence.
Locating, recording and recovering evidence such as fibres, blood, hair, paint or glass using various techniques.
Putting samples into protective packaging and sending them for analysis.
Keeping written records, producing statements and updating systems with details of evidence.
A ninhydrin solution is commonly used by forensic investigators in the analysis of latent fingerprints on porous surfaces such as paper. Amino acid containing fingermarks, formed by minute sweat secretions which gather on the finger’s unique ridges, are treated with the ninhydrin solution which turns the amino acid finger ridge patterns purple and therefore visible.
A stain obtained after a thumbprint is treated with ninhydrin.
Ninhydrin was discovered in 1910 by the German-English chemist Siegfried Ruhemann (1859–1943). In the same year, Ruhemann observed ninhydrin’s reaction with amino acids. In 1954, Swedish investigators Oden and von Hofsten proposed that ninhydrin could be used to develop latent fingerprints.
Contamination is the introduction of something to a scene that was not previously there. This means trace materials are added to a crime scene after the crime is committed. This can happen before, during and after authorities take samples of the evidence from a scene. Many people can contaminate the evidence at a crime scene, including witnesses, suspects, victims, emergency response personnel, fire fighters, police officers and crime scene investigators. Juries expect to see forensic evidence before they make a decision in a case which relies on that evidence. Because of this, attorneys on both sides try to discredit forensic evidence that does not support their clients’ interests. This requires crime scene investigators to be especially careful to guard against contamination in the forensic samples taken from a crime scene. A misscarriage of justice can occur when these procedures are not carried out carefully and accurately.
As Paul hoped, women are playing a leading role as Scene of Crime Officers.