DNA database

• list the history of DNA database

  • 1995: 1st database in UK
  • 1996: in NZ
  • 1998: FBI
  • 2001: NCIDD <— AUS
• NCIDD


  national crime invest DNA database
• database 


  collection of computer files with entries to be searched
• forensic dna database 


  collection of electronic dna profiles to search for potential matches
• give examples of dna database

  1. STRbase: STR, y and x
  2. YHRD: y-chr haplotype ref database
• aims of YHRD

  1. generate reliable Y-STR haplotype frequencies estimates for Y-haplotype for kinship cases
  2. assessment of male pop stratification among worldwide pop refelected by Y-STR and Y-SNP freq database
  3. provisions advanced tools and further resources with Y-STR and Y-SNPS
• how big is YHRD database

  125 national database
• mtDNA database


  empop: European mito pop platform

  50,000 samples
• list things to create DNA database

  1. collecting specimens from known crim
  2. analyse specimens and place profiles in database
  3. compare unknown with known
• what processes to create DNA database

  1. DNA profiles from allele freq
  2. use pop allele freq
  3. use genetic formula
  4. estimate rmp or LR
• databank 


  collection of samples
• pop dataset 


  collection of DNA profiles used for stat cal
• explore how dna database are generated

  1. decide on the number of samples with the ethical group (at least 100+)
  2. gather samples through the blood bank
  3. analyse desired genetic loci
  4. determine allele freq for each loci
  5. perfom stat test on data: HWE for allele indep and linkage for locus indep
  6. ethical group 1 and 2 to examine the genetic distance
  7. use the database to estimate observed freq
• what is population database

  • allele freq which is a subset of total pop
  • 1,000 donors
• how to determine which pop database

  1. use pop macthes with the suspect background
  2. use witness and videos
  3. range of profile freq across all pop
• how to establish forensic database

  1. commitment of the government to provide the samples
  2. common set of DNA markers for comparing
  3. standard software/computer format to tranfer between labs
  4. quality standards
• UK database

  • April 1995
  • uses 6-10 loci
  • collected from UK, channel island and isle of man
  • 5.9 million profiles from 647,000 cases
  • run by the home office since 2012
• 2 types of DNA profiles of NDNAD (UK)

  1. individual: every person arrested
  2. crime scene: from samples
• how does a database help with crimes

  1. ID or eliminate suspects
  2. ID key witness
  3. MPI
  4. comaprsion of profiles
• CODIS 


  combine DNA index system

  • links serial crimes and unsolve cases with repeat offenders
  • oct 1998
  • 50 states
  • US
  • requires >4 RFLP markers which is 13-16 STR
• NDDB

  • canda, National dna database bank of canda
  • july 2000
  • links all Canadian provinces
  • convict index >13,000 samples
  • crime scene index >3,500 samples
• NCIDD

  • aus
  • 2001
  • in 2018: 873,00 profiles
  • uses 9 STR loci and a sex gene but now uses 13 STR
  • combines all data
• what do we use NCIDD for

  1. Link crimes with no suspects
  2. ID suspcts and eliminate them too
  3. determine any serial offenders
• premises 


  90% of crime is committed by 10% of population
• warm links vs cold links

  cold: links b/w scene and person police have not suspected = creates a new lead

  warm: link b/w scene and person police has suspected = strengthen the belief
• advantages vs disadvantages of database

  ad: - shared across boarders

  • reduces invest time and targets resources
  • prevent crime as detterance
  • make assocations
  • link rate in aus 1 in 3 and USA/UK us 1 in 2

  dis: - privacy and security

  • inappropriate use - corruption
  • profile rentention when not found guilty
• familial matching

  • occurs when DNA from unsolved crime has not links
  • its is searching for related profiles based on the belief that crime tends to run in family and small radius from home
• how familial matches help

  1. link blood relatives to assit police
  2. help dtermine if scene profile links to blood relative of a person in the database
• how does familial matching work

  • list of possible link genome computer
  • mtDNA and Y-chr test used to confirm bio links
• limitations of familial matching

  • in aus, it is governed by the state polcies which has strict limitations
  • contentious ethical and logical issues
  • limited to serious crimes and if all lines are exhausted