On Saturday the 20th of November 14 Queketts enjoyed the day at Reading University, learning something of forensic science. The workshop was led by Pam Hamer, assisted by two of her former colleagues, Pauline Russell and Carol O'Mahoney. Kit Brownlee of the University lent a hand with the equipment.
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Pam's enthusiasm was infectious. Pauline Russell and Carol O'Mahoney are just behing her. |
Pam started by giving us a talk on how different glasses can be identified: Refractive Index (RI) is the key here. Using a special oil whose RI changes predictably with temperature, it is possible to measure the RI to four places of decimals! This is done by watching the fragments immersed in the oil as it cools after heating, and taking the time the glass disappears and then appears again as the RI changes. (When glass is immersed in a liquid of the same RI it is, of course, invisible). Although we weren't able to measure the temperature exactly we were able to compare three kinds of glass for the differences in RI.
Later we looked at paint, both at the surface texture, and in cross sections bought along by Pam. The surface textures can be very revealing under a low-power stereo, as can the colour match between two suspect samples.
| Pam sets out some of the samples. |  |
Finally we learned about fibres - mostly using polarised light. Pam explained the different orders in the colour patterns that can reveal much about fibre types. We were able to sample a range of fibres, some artificial, such as acrylic and nylon, some natural such as cotton and wool.
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We were able to eat our lunch sandwiches in the comfortable Common Room appropriately in the Food Studies Department of Reading University. Plenty of hot drinks and biscuits were availabl |
After lunch came the high spot: we were
going to have a real 'crime to solve!
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Left: Pam lays out the evidence. This included glass from the burgled house, sweepings from the suspects' car, fibres from the car seat and fibres from the clothes the suspects were wearing. Using the techniques we had learned in the morning and early afternoon, we now had to try to establish links between the house, the car and the suspects |
A couple of hours of serious work followed, with lots of head-scratching and animated discussion. At the end Pam asked for the results and then revealed the conclusions we should have come to, not in some cases, the same! It has to be admitted that this "expert witness's" evidence was torn to shreds by defence councel!
And so ended a most intriguing and stimulating day. Our thanks to all concerned, including of course, Allan Brinkworth, Hon Business Secretary, for organising the day in the first place.