Chris Gee

May 24

Bloodstain Pattern Analysis - My First Experiment

Those of you who follow me on Twitter will probably be tired of all my posts to do with my final project on Blood. In my defense I took three weeks off work to complete the project, so I haven’t had much else to tweet about! My 5,000 word essay has now been completed, and is the last piece of work required for my C.S.I foundation degree (run through the College Of Policing).

Part of this essay required me to do an experiment. The essay was based on the interpretation of bloodstains at a scene I’d previously been to. At this scene someone had climbed through a window, leaving a bloodstain behind on the window frame. What I hoped to find out is what direction this stain was deposited and how much blood was likely on the subject.

I obtained a small amount of horses blood which I bought from a local Equine Hospital. I also loaned a window from a local double glazing company. Both companies were more than happy to help, to which gained them a glowing report in my final acknowledgments.

Now before anything anywhere can be started, you have to consider three words… HEALTH AND SAFETY. I completed a Risk Assessment form, covered the room in plastic sheets, and dressed myself in Personal Protective Equipment. I even put a sign on the door, warning people what was on the other side!

Using a syringe (without the needle) I deposited blood onto my gloved arm and pushed against the window frame. The first motion I took was going away from my body, in an outwards direction. The following stain was made using 2ml of blood.

Notice how a lot of the blood is collected at the edge of the window, and drips down under the influence of gravity. A small amount is then smeared outwards. At the final contact position a bit more blood is present, as the blood needs to escape from the two colliding surfaces and is forced outwards. If you look closely you can see a vertical line in blood near the ruler, and a bit more blood near the 5cm and 6cm markers.

In the next image I used 1ml of blood (ignore the top stains away from the ruler).

For just 1ml of blood a stain this size can be deposited. Again the blood has collected and flowed down the window at the initial contact point. The change in the window’s shape also causes most of the blood to collect near the seal. This time the blood has been forced upwards as it has again been looking to escape from between my arm and the window.

I then placed a single drop of blood onto my arm, which I photographed.

And here’s the stain it left behind.

Quite a substantial stain for a drop of blood. The same rules seem to apply as the previous, just leaving a little less blood behind. Less blood has flowed downwards. Now I’ll show you what happens when I change motion. Stood in the same spot, I pulled my arm towards me, starting from outside the window and moving it closer to the seal. This stain was produced using 1ml of blood.

Notice how the blood has mostly collected and flowed down the window at the opposite point to my previous motion. There’s also a heavier stain throughout the main bloodstain. I have put this down to how the window might force me to make less contact/pressure when pulling my arm towards me, due to its shape.

Using a single blood drop, measuring similar to the drop I photographed, and the same motion I created this stain.

The blood again flows down on the opposite side. The window edge acts almost like a razor, taking the majority of blood off my arm at the initial contact point.

I used this experiment to talk about the scene images, and predict the motion/direction applied when depositing the stain. I was also able to gain a rough idea about how much blood came into contact with the window. Of course not all of this was down to an experiment. I got stuck into quite a few books. I was able to use both the experiment and theory I’d learned to discuss the scene.

More posts about my project will be published soon.

May 10

Almost time for my experiment. Everything is in place ready for tomorrow. #experiment #science #blood #bpa #forensics

Almost time for my experiment. Everything is in place ready for tomorrow. #experiment #science #blood #bpa #forensics

May 09

My laser protractors have arrived, almost set for my experiment with blood! #maths #science #forensics

My laser protractors have arrived, almost set for my experiment with blood! #maths #science #forensics

May 05

My little blood book! All my notes about bloodstain pattern analysis is going in this! #forensics #blood #homework

My little blood book! All my notes about bloodstain pattern analysis is going in this! #forensics #blood #homework

Apr 25

My First Post Mortem - #csidiaries

I began my first job within the Scientific Support Branch (now called Forensic Investigations) in 2008, and started off as a Scientific Support Assistant. I was 20 years old when I began this role, and hadn’t had a huge deal of experience or exposure to the real world of crime. The SSA role was a perfect way to ease me into the department. I was an essential part of the office, but played more of a background role. I was responsible for the transportation of all exhibits, the documents for forensic testing of exhibits, all stock orders, seized property by police officers, and many more tasks.

I personally saw this role as a stepping stone as the ultimate goal was to become one of the team who is out on the frontline. What I was concerned about at this age was ‘could I stomach it?’ Could I be strong enough to deliver a decent service to the police force and public? I knew I would have to gain the necessary experience before being called upon, to know I could handle it.

I attended my first Post Mortem at the age of 21 or 22. Still rather fresh faced. A colleague was due to travel over to the Mortuary, and asked if I’d like to give him a hand. I remember having that rush of adrenaline as he asked me, the heart beating so loudly you can almost hear it.

I was nervous for two reasons. The first, I was about to see someone who had passed away. Something I’d never seen before, and growing up I’d pretend it didn’t happen. It was something you’d see on the TV but never in the real world. The second reason was just, if not more scary than the first. As he asked me I knew that today would be the day I find out if I’m cut out for the role. If I couldn’t handle it then I would be back on the job market. It would be the turning point in my career.

When we first arrived I was hit by the smell. A nice clean smell. The smell of cleaning products. I kept close to the experienced SOCO, like a cub would stay with its mother when exploring unknown territory. We passed through the corridors and got changed into our PPE (Personal Protective Equipment) which included a scene suit, mask, overshoes, gloves and hairnet.

We walked into the main Post Mortem room and on the table was the body bag. My colleague and I set up on a different table, laying out equipment the Pathologist would need. Some of which were swabs, exhibit bags, fingernail clippers, hair collection kits.

As the body bag was opened the first thing that struck me was the deceased gentleman’s face. The shocked expression he displayed was terrifying. What disturbed me the most was that he looked in pain, pain caused by the injuries he’d sustained. It was simply horrible to think that those were his last moments. His eyes glued to me, as if he was asking me for help. And I think that was the turning point for me, the moment when I realised I could do it. Because I have that passion to help people. I’ve always tried my best to be there for my friends and family, and here I had to opportunity to help another person. Although this time it would require a lot of strength on my part. I looked at him and made a promise, that I would stand alongside a team of people giving 100 percent. I would perform to the best capacity I could.

The Pathologist carried out his work, and I dealt with all his exhibits. I would hand him a swab, he’d swab the required area and hand it back to me. I would then seal the swab inside an exhibit bag and write the description on the outside. This task becomes very fast paced when there’s lots of swabs and other samples to be taken; the Pathologist won’t stop on your part. They will then spend hours looking for abnormalities and inconsistencies on that person. I would rank Pathologists as being one of the most thorough people on the planet. All of which I have worked with appear to look at every detail until they’re satisfied with the cause of death.

Since that day I have continued to attend Post Mortems, and they’re never easy. Seeing someone who’s passed away is never something I look forward to as the child in me always likes to pretend it doesn’t happen. But the rest of me tries to stand strong to make sure the deceased, and their families, are fully respected.


If you have been affected by anything in this article please don’t hesitate to seek help. Asking for help is never a weakness, it requires a great amount of courage. A great charity which I highly recommend is Victim Support. A relative of mine works for them, and I know you’d be we’ll looked after. They can offer ongoing support. Visit victimsupport.org.uk for more information. Alternatively, I’d advise you to visit your GP, who can put you in touch with Time To Talk. Another great organisation who offer counselling. If the Police can be of help, please contact us on our non emergency number 101.

Apr 23

My weapon of choice! #photography #forensics #nikon #nikond300

My weapon of choice! #photography #forensics #nikon #nikond300

Apr 18

Day off, and guess what I’m doing! #homework #books #forensics #science

Day off, and guess what I’m doing! #homework #books #forensics #science

Mar 19

#SOCO #CSI #forensics #forensicscience #police #crimescene

#SOCO #CSI #forensics #forensicscience #police #crimescene

Mar 15

I’m alway happy to work alongside others, even ones with fur and 4 legs! #dog #searchdog #police #forensics

I’m alway happy to work alongside others, even ones with fur and 4 legs! #dog #searchdog #police #forensics

Feb 28

A letter I’ve written to a 10 year old who expressed an interest at being a SOCO one day.

A letter I’ve written to a 10 year old who expressed an interest at being a SOCO one day.