AN EXPERIENCED forensic investigator who was one of the first to the scene of the murder of Olly Stephens and the death of Pc Andrew Harper has movingly described what it is like to play a crucial part in bringing criminals to justice.

Sarah, a civilian investigator, has worked at Thames Valley Police for 21 years and gave a demonstration to the press on Thursday, August 24, as part of the force's media open day.

Speaking about her role, Sarah described how the CSI plays a key part in the earliest stages of investigations and how gathering evidence can be make or break.

There are 200 civilian forensic team investigators working across Thames Valley. Outside of the emergency and immediate cases, the team operates on a daily basis. When the CSIs arrive in the morning, there is a pick-up list of jobs that have come in overnight. They are prioritised accordingly. A murder for example will always warrant a visit from CSI.

Once at the scene, they get to work. Sarah said: "If it’s a major incident my first thoughts are – have I got a cordon in place? Have I got enough officers to stop the public from coming in? Is it safe? We’re single-crewed units, we’re working alone so that’s the sort of thing I think about.

“And then you’re thinking about the first initial witnesses, the first statements from police colleagues, assessing what tallies up and having to start our processes, making assessments on where to start with getting that evidence.”

The type of evidence they will be looking at sound obvious - footprints, discarded items, finger prints etc. But now there is the digital footprint too, with a separate growing unit looking at mobile phone signals, social media searches and location tracking.

But there is an emotional element of it too.

Sarah said: "We go to a lot of major incidents that can be quite traumatic.

She said: "Because I've been in the force almost 21 years now, I've spent all my career in Berkshire so I've involved in a lot of incidents as a CSI. I went to Didcot Power Station collapse, I attended Rowe Court. I was the CSI in attendance on the night that Olly Stephens died. I've unfortunately been quite a lot and last week was the anniversary of Pc Harper's death where I was also in attendance."

And while it is a heavy task, Sarah said: "I am proud to have played my part in those incidents."

On a day-to-day level, Sarah spoke about the satisfaction that can be gained from catching a burglar or identifying a sexual predator.

She said those are some of the most rewarding moments, saying: “For me, when I get to a burglary and you’re there with the victims, you have that interaction with them and when you find that fingerprint or that bit of evidence that takes it to court, you’ve caught the burglar and you know you’ve made a real difference.

“Also with sexual assaults where we manage to identify offenders and recover evidence at scenes, that’s always a positive feeling.”

CSIs are paid on average between £24,000 to £35,000 a year plus allowances.

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