The Evolution and Reliability of Fingerprint Evidence

Historical Background

• Date of First Crime Solved by Fingerprints: October 17, 1902
• Victim: Joseph Reibel, murdered at his workplace
• Key Discovery: Shard of broken glass with bloody fingerprints
• Investigator's Action: Manual search of police fingerprint records
• Suspect: Henri Scheffer, previously arrested for theft, later confessed
• Significance: First crime in Europe solved using fingerprints alone

Importance of Fingerprints Today

• Current Usage: Fingerprints as a common type of evidence in criminal courts
• Uniqueness: Improbability of two identical fingerprints, even among identical twins

Development of Fingerprints

• Formation:
  • Begins in the womb at about 7 weeks
  • Skin on hands and feet swells to form smooth raised pads
  • Buckling and folding occurs around 10 weeks, influenced by genetics and environment
• Randomness: Unique patterns arise from the random environmental factors affecting development

Advances in Forensic Science

• Historical Studies:
  • Interest in fingerprints began in the late 1800s
  • Early 1900s saw prosecution using fingerprints in courts
• Types of Prints:
  • Visible Prints: Patent and plastic prints
  • Latent Prints: Invisible, consist of water, oils, proteins, and salts
• Detection Methods:
  • Dusting with fine powder for latent prints
  • Chemical developers like Ninhydrin for porous surfaces
  • Experimental techniques using electrical charges to detect corrosion from fingerprint salts

Matching Fingerprints

• Process:
  • Collection and matching with potential suspects
  • Use of automated systems to narrow down fingerprint database matches
  • Certified experts analyze ridge details and spacing of oil pores
  • Blind verification by a second expert before submitting to justice departments

Challenges and Limitations

• Human Error:
  • 2011 study indicated false matches occurred 0.1% of the time
• Print Quality Issues: Smudged, distorted, or overlapping prints complicate matching
• Lack of Standards: No universal guidelines on ridge detail analysis for matches
• Recommendation: Fingerprint evidence should not be the sole basis for conviction

Conclusion

• Ongoing efforts to improve and standardize fingerprinting processes
• Fingerprints have significantly impacted crime scene investigation and evidence collection.