My #Friday evening attire! #forensics #science #coolface
A couple were making use of the nice weather we’ve been having in the south of England recently, and decided to build a new shed in their back garden. Whilst digging up parts of their lawn to lay down the concrete, they stumbled across an item that changed their entire day - a bone. Instead of giving it to their dog they contacted police, who turned up and collected the bone from them. The big question was, whose bone was it? If it were human we could be looking at a suspicious event and a murder investigation could be launched. A police officer remained at the scene, guarding it, whilst another transported the bone to our department.
The bone was handed to me and I immediately set to work. We have a really efficient way of identifying if a bone is human or animal, and all it really requires is a camera and email account. We call on the expertise of a Forensic Anthropologist and Archaeologist at Cellmark Forensics, trained in the identification of bones. They require good quality photographs to ID each bone.
I cleaned down our photographic stand, placed a new strip of brown paper down, and set up my camera. The camera is secured tightly to avoid camera shake, and I can use additional lighting either side.
I used a Macro lens in my camera to get finely detailed images. I took a selection of images from different angles, something that the Scientist requires.
The Scientist also requires a scale in every image, so size can be determined. Another angle showing the other side…
A photo showing the end…
These images, along with others, were emailed to the Scientist who gave me a result in a matter of minutes. NOT HUMAN. A relief for the owners of the home, as their garden could’ve seen a major incident scenario spread across the summer lawn. It would’ve surely turned the grass brown. I communicated the Scientists findings to the police officer guarding the garden, and this was passed onto the owners. We were all extremely grateful for the owners report and cooperation throughout the day.
It’s normally a dog walker who makes these finds. This time, a shed builder.
This blog is dedicated to one of my followers on Twitter, @Vidocq_CC who loves cold cases! Thank you for taking an interest in this whilst it was Tweeted on the day.
The doorbell to the office rang and I keenly hopped out of my seat. I opened the door and greeted Detective Constable Alison Hoad, who held a rather large exhibit sack in her hands. She explained the reason for her visit, that she had been passed a job to deal with that held little hope. A few months prior to her visit human bones were found by a dog walker in an area of Sussex, and with these bones amongst all the dirt and vegetation was a shoulder bag. The bag was in close proximity to the bones, with a high potential the two were related. DC Hoad asked me to search the bag to see if any clues could be found that would help identify the deceased person.
I opened up the exhibit sack, removing the shoulder bag from it. I pulled off all the dead snail shells and set to work, brushing away all the dirt. Inside the bag were a pair of reading glasses without the lenses, with badly damaged frames. A wristwatch came out next, and both these items were photographed. I then pulled out three door keys, stuck to the lining of the bag, which were all badly corroded. Two of the keys were in really bad condition and appeared as if they’d fall apart any second. But I closely photographed another key.
This key was in better condition than the others, but still not ideal. You could make out a ‘K’ and ‘20’. I performed a quick search on the internet and this symbol was very similar that of KABA locks.
Together the two of us combined our knowledge and came up with an idea. DC Hoad advised that some keys have serial numbers on, and I suggested we treat the key with a chemical to try and clear the outer corrosion. I called in a specialist, SOCO Richard Stringer, who rubbed Acetone onto the key using cotton wool, and as if my magic the corrosion started to vanish. This technique is more commonly used on cloned vehicles. As you can see the key started to show that nice silver colour that your door keys have, and with our delight a serial number could be seen on the back.
We both did some ringing around and many phone calls later, we found the door it fitted. DC Hoad made a phone call to theNPIA Missing Persons Bureau and one person was showing with links to this address, who had been missing since 1999. She was then able to visit the family and find out more details. Like a half completed jigsaw puzzle, the pieces started to fit better and better together. The person had links to the area they were found at by the dog walker, and had genetic similarities to the family. The LGC Forensic Service Provider performed a basic DNA comparison with the deceased’s relative, and came to the conclusion that there was a 1 in 40 chance of them being related. During the Post Mortem at the beginning of the investigation, the Forensic Anthropologist gave an indication towards the age the person was when they died. But no cause of death could be determined. The Coroner was happy that no further work was needed, which included more work I haven’t mentioned for ambiguity, and accepted this identity.
The family were notified of all findings, and kindly agreed for me to do this blog. We at Sussex Police strive to help and bring closure to families who need it. DC Hoad set a fantastic example of how persistence and attention to the finer detail can really pay off. Everyone else had overlooked the keys, but our two minds made this cold case heat up. I’m really pleased we could present our findings to the family and offer them their relative back, someone they had lost for so long.
#OnTheFingerprintTable tonight is 1 x Crowbar! #fingerprints #forensics #soco #csi
Elimination fingerprint forms returned by home owners. #fingerprints #forensics
Lookit, a tiny revolver. #tinythings #firearm #gun #revolver #cutebutdeadly
Being able to age a bloodstain would be an essential tool for a Crime Scene Investigator. You could pinpoint a rough time the offence occurred; potentially proving/disproving a suspect’s statement. For example, blood is found on a smashed shop door where a robbery has occurred. The blood identifies a person who then claims they deposited the blood a week ago when they came in as a customer. If a Scientist could put a time stamp on the bloodstain, this may prove or disprove the suspect’s statement.
It has been suggested that the appearance of blood may give an indication as to how old a stain is. As described in a book titled ‘Fisher’s Techniques of Crime Scene Investigation’, blood can react with the background and form different colours, for example if a stain has been left on wallpaper. A relatively fresh bloodstain is normally reddish-brown in colour and glossy. The glossy effect slowly fades after the stain has been subject to heat, wind, and weather conditions. Blood can also appear in grey, blue and green hues. The issue when aging blood by its appearance is that too many anomalies can alter the look of the stain. Blood will dry quicker in hotter conditions, and will react differently on various surfaces. Another issue will arise when the examiner comes to photograph the mark. The stain colour may look differently in the photograph than to the human eye, as the camera is adjusted to the surroundings; something the human eye does automatically. If two examiners took an image of the same stain, but the camera settings or lighting conditions differed slightly, the stain will likely be of different hues in the two photographs.
However these ideas only allow for a rough estimate of how old a bloodstain is. An AFM (Atomic Force Microscope) is used to measure the force between a probe and the sample. Indentation experiments with an AFM are generally applied in measuring the elastical properties and Strasser’s research uses this method to measure the altication of elasticity of blood cells. The results showed that no alterations in the erythocytes or cracks in the bloodstain took place after an observed period of 31 days, using AFM imaging. However, when measuring the elasticity of a bloodstain the AFM showed a decrease of elasticity as the sample ages. The work is ongoing, and not a final product, as a few limitations were discovered during this research. The measurements displayed a high standard deviation, possibly explained by the non-homogeneous composition of the blood clot. These components seem to influence the elasticity parameters, potentially making the tests inaccurate.
A recent journal by Rolf H. Bremmer, and others, breaks down blood by its components and looks at ways to age the bloodstain using a variety of methods. The technique using an AFM is highlighted for use with Red Blood Cells, and consideration is given to aging White Blood Cells by using their nucleus. Platelets are not considered applicable due to the fast and complex mechanism of coagulation. Overall, no completely viable technique could be discovered and all practices are said to still be in their experimental phase.
 Tilstone, W.J., Hastrup, M.L., and Hald, C. (2013). Fisher’s Techniques of Crime Scene Investigation. 1st ed. Florida: CRC Press. 220.
 Swanson, C.R., Chamelin, N.C., and Territo, L. (2000). Criminal Investigation. 7th ed. USA: The McGraw-Hill Companies, Inc. 99.
 Zhong, W.L. (n.d.). Fundamental Theory of Atomic Force Microscopy. Available: http://www.nanoscience.gatech.edu/zlwang/research/afm.html. Last accessed 20th May 2013.
 Strasser, S. et al. (2007). Forensic Science International. Age determination of blood spots in forensic medicine by force spectroscopy. 170, 8-14.
 Bremmer, R.H., de Bruin, K.G., van Gemert, M.J.C., van Leeuwenm, T.G., and Aalders, M.C.G. (2012) Forensic Science International. Forensic quest for age determination of bloodstains. 216. 1-11.
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.
Almost time for my experiment. Everything is in place ready for tomorrow. #experiment #science #blood #bpa #forensics
My laser protractors have arrived, almost set for my experiment with blood! #maths #science #forensics