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Powder Suspension Operational Perspectives

Explore the operational validity and effectiveness of new techniques in powder suspensions for forensic services. Partnership with HOSDB and Strathclyde University. Results impacting operational practices. History of significant recovery rates, particularly in vehicle crime and fingerprint identification. Research on drug contamination removal and firearm analysis. Comparison of techniques and enhancement methods.

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Powder Suspension Operational Perspectives

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  1. POWDER SUSPENSIONSOPERATIONAL PERSPECTIVESPSA FORENSIC SERVICES GLASGOW

  2. Background Academic Research - ‘New techniques’ Operational validity Better? Effectiveness Efficient Ease of use POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  3. Partnership working with HOSDB and Strathclyde University 10 years MSc students for 3 months Operational problems (Substrate/contamination/poor results/comparison) Scoping study agreed by User group Results must have operational impact POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  4. History 2004 student project into recovering marks from fire damaged items Information gained allowed further exploration Short operational trials and joint research recovery of marks, indicated useful process for contaminated and/or wet items, fire damaged vehicles Results indicated further uses - unknown environmental factors POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  5. Results Significant increase on items which had been wetted (60%) Vehicle crime - cars and cowlings > 80% on other processes quicker - 3 hours Further recovery of marks when used as ‘last’ process on other non-porous substrates Report results to HOSDB FFF User group POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  6. Results Cowlings - 100% increase in recovery 40% casework results in marks - 78% increase in identifications - 300% decrease in marks with little ridge detail ease of photography compared to fluorescence Resulted in HOSDB Manual of Fingerprint Development Techniques re-written. New chapter published April 2010 and charts changed to include powder suspension POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  7. POWDER SUSPENSION OPERATIONAL PERSPECTIVE Murder:- footprints on bonnet

  8. POWDER SUSPENSION OPERATIONAL PERSPECTIVE Powder and photography

  9. POWDER SUSPENSION OPERATIONAL PERSPECTIVE After Powder Suspension

  10. Drugs contamination on packaging Poor operational recovery rates on contaminated packaging can contamination be removed? what is best technique for mark enhancement? Is there a better way? MSc project based on common packaging types and common contamination (powders/glucose solution) POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  11. Results Best removal technique for powders Soft squirrel hair brush light brushing Best enhancement technique ‘Brown Taped’ packaging - VMD/Glue and dye ‘Silver Taped’ packaging - Powder Suspension ‘Sandwich bags’ - Superglue and powder/VMD Best removal technique for Amphetamine Paste Gentle rinse with running water Best overall enhancement technique Powder suspension POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  12. POWDER SUSPENSION OPERATIONAL PERSPECTIVE Firearms Operational poor results, 2%, compared with DNA, 10% Is current process best? Any other factors (handling, condition) 3 strands to project Back to basics comparison 9 techniques Comparison of best 5 over 7200 fingerprints 4 timescales Declared trial with Ballistics Dept

  13. POWDER SUSPENSION OPERATIONAL PERSPECTIVE RESULTS SG & BY40 69% with 32% deemed identifiable SG & White Magnetic Powder 64% with 32% identifiable White Powder Suspension 92% with 47% identifiable Black Powder Suspension 68% with 34% identifiable White Powder 65% with 42% identifiable

  14. Declared trial Using the same donors, prints deposited on 12 guns and packaged in poly bags as per current submissions Both White Powder Suspension and Superglue and BY40 used 86% less prints recovered Small numbers of repeats, further work required however results indicate significant loss. WPS recovered more marks than SG and more detail POWDER SUSPENSION OPERATIONAL PERSPECTIVE

  15. POWDER SUSPENSION - OPERATIONAL PERSPECTIVEQUESTIONS?? SPSA FORENSIC SERVICES GLASGOW

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