• Principal scientist at Netherlands Forensic Institute
• Professor in Criminalistics at Leiden University
• charles-berger.com

1. Introduction / definition / forensic disciplines
2. Forensic disciplines (continued) / history / classical principles / deduction
3. Probabilistic reasoning; Evidential strength: the likelihood ratio
4. Forensic reporting, conclusion scales; Fallacies

• Forensic science is the application of scientific principles and technological practices for the purposes of justice in the study and resolution of criminal, civil and regulatory issues.

American Academy of Forensic Sciences, 2003

• Forensic science is a systematic endeavor to describe how events of legal concern have happened based on observation, hypothesis formation, and experiment.

Sensabaugh, 1997

• Criminalistics is the science of individualization.

Kirk, 1963

• Criminalistics is the science of reasoning backwards.

Berger, 2009

• that profession and scientific discipline directed to the recognition, identification, individualization, and evaluation of physical evidence by application of the physical and natural sciences to law-sciences matters.

American Board of Criminalistics

• that professional occupation concerned with the scientific analysis and examination of physical evidence, its interpretation, and its presentation in court.

California Association of Criminalists

Forensic science also includes disciplines that:

• are not a physical or natural science, such as psychology of law and forensic accountancy;
• are not (mainly) aimed at finding the truth, such as forensic psychology and psychiatry.

• Kriminalistiek (B), Kriminalistik (D), Criminalistics (US), Forensic Science (UK)

Criminology

The scientific study of the causation, correction, and prevention of crime.
Subdivision of the larger field of sociology.

• Not on all the separate disciplines, but on what they have in common
• Not on the analysis (technology), but on the interpretation (principles)

• More generally valid within forensic science
• Less temporary
• Different from ‘normal’ academic science
• More useful for legal practitioners

• On behalf of its clients, the NFI uses state-of-the-art technology and science to provide high-quality forensic services

• Aimed at truth,
  guided by science,
  for a safer society

• The NFI does not have prosecutorial powers or duties
• The NFI does not have a supervisory role over the Public Prosecution Service, the police or other clients
• The NFI is an independent services provider
• Requesters are free to choose any forensic services provider

• Examinations in criminal cases (70%)
• Research and Development
  (15%)
• Center of knowledge and
  expertise (15%)

• DNA analysis
• non-human DNA analysis
• hair analysis
• blood pattern analysis
• age estimation living persons
• forensic anthropology
• forensic medicine
• forensic pathology
• toxicology

• waste products and risks
• arson, technical and material analysis
• explosions and explosives
• tool marks
• traffic accident
  investigation
• weapons and
  ammunition

• forensic element analysis
• gunshot residue analysis
• glass, paint, tape and
  glue analysis
• chemical identification
  analysis
• fiber and textile analysis

• drug analysis
• drug production investigation
• drug comparison

• closed and open systems
• data communication
• image analysis and biometry
• document examination
• handwriting examination
• face comparison
• speech and audio analysis
• fingerprinting

• front desk (intake of exhibits)
• forensic advice/forensic intake
• Mobile Forensic Team
  (MFT)
• forensic archeology

• number of products delivered: 67600
  • Biological Traces: 47000
  • Digital and Biometric Traces: 1000
  • Chemical and Physical Traces: 13600
  • Specialist Services and Expertise: 6000
• staff members: about 600

• Public Prosecution Service
• Police
• The Judiciary (judges)
• Fiscal Information and Investigation Service
• National Coordinator for Counter-Terrorism
• Netherlands Competition Authority
• Immigration and Naturalization Service
• United Nations
• International Criminal Courts
• International Tribunals
• EU

Nationally and internationally with:

• forensic institutes
• universities and colleges
• knowledge institutes
• companies

• Questions
  • Link weapon to bullet and cases to each other
  • Classification
• Evidential material
  • Firearms, bullets, cartridges
• Analysis
  • Comparison microscope
• Interpretation
  • Expert opinion
  • Databases

• Questions
  • Find source, or link marks
  • Classification
• Evidential material
  • Shoes, shoe marks
• Analysis
  • Microscope, 2D-prints, 3D-molds
  
  
• Interpretation
  • Expert opinion

• Analysis
  • Observed features
    • Sole pattern
    • Size
    • Manufacturing
      irregularities
    • Wear, damage
  • Comparison
• Interpretation
  • Expert opinion
    • Knowledge
    • Experience
    • Databases

• Questions
  • Classification
  • Source
• Evidential material
  • Liquids
  • Fire debris
• Analysis
  • GC-MS
• Interpretation
  • Databases
  • Expert opinion

• Questions
  • Classification
  • Quantification
  • Drugs intelligence
• Evidential material
  • Powders, pills, liquids
• Analysis
  • Micro-chemical tests
  • GC-FID, HPLC-UV, GC-MS
• Interpretation
  • Databases
  • Expert opinion
  • Statistical models

• Glass / fibers / paint / polymers
• Questions
  • Source
  • Transfer, crime scene suspect
  • Activity
• Evidential material
  • clothes, shoes, cars, objects

• Glass / fibers / paint / polymers
• Analysis
  • Microscopy (all)
  • Refractive index (glass)
  • X-Ray Fluorescence - XRF (glass)
  • FT-IR (fibers, paint, polymers)
  • Py-GC-MS (paint, polymers)
  • Inductive Coupled Plasm Mass
    Spectrometry - ICPMS (glass)
• Interpretation
  • Expert opinion
  • Statistical models

• Questions
  • Reconstruction, speed
• Evidential material
  • Vehicles, tire marks
• Analysis
  • Monte-Carlo simulation
• Interpretation
  • Based on statistics and simulations

10 μm

• Questions
  • Is there GSR?
    • On suspect / victim
  • Shooting distance
• Evidential material
  • Stubs (sampled hands)
  • Clothing
  • Ammunition
  • Firearms

• Analysis
  • Chemical tests
  • Scanning Electron
    Microscope
  • X-ray analysis
• Interpretation
  • Expert opinion

Alec Jeffreys, 1984

• Questions
  • Find DNA
  • Whose DNA is it?
  • How did it get there?

• Analysis
  • Autosomal DNA profiling (STR)
  • Single or mixed profiles
• Also:
  • Y-chromosomal DNA
  • Mitochondrial DNA
  • RNA (cell type)
  • LCN (Low Copy Number) or low template DNA

• Comparison
  • Does the trace profile ‘match’ the suspect’s profile?
• Interpretation
  • Source of trace, random match probability
  • And less often, but increasingly:
    • When and how did the trace get there?
    • What kind of cells are they?
  • Context is important
    • Which evidential material?
    • Where was it found?
    • Relation material and victim / suspect / perpetrator