Crime scene investigators

Collecting evidence from a crime scene can involve looking for fingerprints, footprints, or foreign objects to combing a carpet for a single hair.

This painstaking work is carried out by crime scene investigators whose job it is to gather as much evidence left by an offender as possible, that will link him or her to the offence.

Their work could take them to murder scenes, where they might spend a couple of weeks, to houses which have been burgled which might take just one hour.

Challenging and varied role

Kent Police has crime scene investigators based around the county. Their role is to look for and record evidence to help solve a crime. CSIs could be asked to go to a murder scene, a robbery, an arson, a suicide, a burglary, a sexual assault, or to vehicle crime or criminal damage.

When it comes to serious crimes the investigators will arrive at a location wearing white protective suits, so they do not contaminate evidence in any way. If a crime scene is outside they might put up a tent to prevent the elements hampering an investigation.

'Delicate, methodical and lengthy work'

Mark Walsh, principal crime scene co-ordinator with Kent Police, said: 'The work of a crime scene investigator is delicate, methodical and can be lengthy. At a crime scene they could be looking for fingerprints, fibres, hairs, footwear marks or any trace evidence.

'We work to the principle that every contact leaves a trace. If you sit on a chair fibres from your clothes will be left there. They might be miniscule and not visible to the naked eye, but CSIs will find them.

'From a single hair with a root or from a sample of blood or saliva we can find someone’s DNA. This can then be used as evidence to place them at a crime scene.'

Our CSIs investigated 58 deaths at Dover docks in June 2000

CSIs from Kent Police were called in when 58 victims were found dead in the back of a lorry at Dover docks in June 2000. The 54 men and four women suffocated in an airless container after the driver shut the air vent so no-one would hear them. The Chinese immigrants were packed in a space behind hundreds of boxes of tomatoes. The Dutch lorry driver was jailed for 14 years in April 2001. 

The case involved a huge forensic investigation which took CSIs from Kent to Holland to prove the driver’s guilt. The investigators found fingerprint evidence on the wooden partitions found in the lorry, which hid the human cargo and were also able to prove the driver had sawn and handled the wood, so knew exactly what was in the back of his lorry.

A prolific burglar was caught due to evidence gathered by our CSIs

In another case evidence taken by CSIs resulted in a prolific burglar being arrested and charged for 75 crimes years after they had been committed. Fingerprint evidence was taken at each burglary and held on file, as it did not match anyone on national computer systems, but when the culprit was arrested some time later and his fingerprints were taken the offender was then charged with the huge list of previous break-ins.

As well as taking evidence from a scene, CSIs have to spend many hours processing what they have found and they have to prepare detailed statements for court.

Also the trail to catch an offender is a team effort. The civilian CSIs play a huge part, as finders, recorders and collectors of forensic evidence. Their work assists an investigation conducted by their police colleagues. They also work closely with forensic scientists and fingerprint experts and will sometimes need to call in specialists from a range of fields from archaeologists to entomologists, who are authorities on insects.