Weight-of-Evidence for Forensic DNA Profiles

by Balding, David J.

• ISBN13: 9780470867648
• ISBN10: 0470867647
• Edition: 1st
• Format: Hardcover
• Copyright: 2005-03-04
• Publisher: WILEY

Summary

Assessing Weight-of-Evidence for DNA Profiles is an excellent introductory text to the use of statistical analysis for assessing DNA evidence. It offers practical guidance to forensic scientists with little dependence on mathematical ability as the book includes background information on statistics - including likelihood ratios - population genetics, and courtroom issues.The author, who is highly experienced in this field, has illustrated the book throughout with his own experiences as well as providing a theoretical underpinning to the subject. It is an ideal choice for forensic scientists and lawyers, as well as statisticians and population geneticists with an interest in forensic science and DNA.

Author Biography

Editors:
D. J. Balding, Imperial College of Science, Technology and Medicine, London, UK

M. Bishop, UK HGMP Resource Centre, Cambridge, UK

C. Cannings, University of Sheffield, UK

Table of Contents

Preface	xi
Introduction	1	(6)
Weight-of-evidence theory	1	(2)
About the book	3	(1)
DNA profiling technology	3	(1)
What you need to know already	4	(1)
Other resources	5	(2)
Crime on an island	7	(15)
Warm-up examples	7	(3)
Disease testing: Positive Predictive Value (PPV)	7	(2)
Coloured taxis	9	(1)
Rare trait identification evidence	10	(3)
The ``island'' problem	10	(1)
A first lesson from the island problem	11	(2)
Making the island problem more realistic	13	(7)
Uncertainty about p	14	(1)
Uncertainty about N	15	(1)
Possible typing errors	15	(2)
Searches	17	(1)
Other evidence	18	(1)
Relatives and population subdivision	19	(1)
Weight-of-evidence exercises	20	(2)
Assessing evidence via likelihood ratios	22	(21)
Likelihood ratios	22	(2)
The weight-of-evidence formula	24	(3)
Application to the island problem	25	(1)
The population p	25	(2)
General application of the formula	27	(4)
Several items of evidence	27	(2)
Assessing all the evidence	29	(1)
The role of the expert witness	30	(1)
Consequences for DNA evidence	31	(5)
Many possible culprits	31	(1)
Incorporating the non-DNA evidence	31	(2)
Relatives	33	(1)
Laboratory and handling errors	34	(1)
Database searches	35	(1)
Some derivations †	36	(4)
Bayes theorem for identification evidence	37	(1)
Uncertainty about p and N	38	(1)
Grouping the alternative possible culprits	39	(1)
Typing errors	40	(1)
Further weight-of-evidence exercises	40	(3)
Typing technologies	43	(13)
STR typing	44	(6)
Anomalies	46	(3)
Contamination	49	(1)
Low copy number (LCN) profiling	50	(1)
mtDNA typing	50	(1)
Y-chromosome markers	51	(1)
X-chromosome markers †	52	(1)
SNP profiles	53	(1)
Fingerprints †	54	(2)
Some population genetics for DNA evidence	56	(26)
A brief overview	56	(6)
Drift	56	(3)
Mutation	59	(1)
Migration	60	(1)
Selection	60	(2)
θ, or Fst	62	(1)
A statistical model and sampling formula	63	(6)
Diallelic loci	63	(5)
Multi-allelic loci	68	(1)
Hardy--Weinberg equilibrium	69	(6)
Testing for deviations from HWE †	70	(4)
Interpretation of test results	74	(1)
Linkage equilibrium	75	(2)
Coancestry †	77	(2)
Likelihood-based estimation of θ †	79	(2)
Population genetics exercises	81	(1)
Identification	82	(29)
Choosing the hypotheses	82	(3)
Post-data equivalence of hypotheses	84	(1)
Calculating likelihood ratios	85	(9)
The match probability	85	(2)
One Iocus	87	(2)
Multiple loci: the ``product rule''	89	(1)
Relatives of s	90	(2)
Confidence limits †	92	(1)
Other profiled individuals	93	(1)
Application to STR profiles	94	(5)
Values for the pj	95	(1)
The value of θ	96	(2)
Errors	98	(1)
Application to haploid profiles	99	(2)
mtDNA profiles	99	(2)
Y-chromosome markers	101	(1)
Mixtures	101	(8)
Visual interpretation of mixed profiles	101	(2)
Likelihood ratios under qualitative interpretation	103	(5)
Quantitative interpretation of mixtures	108	(1)
Identification exercises	109	(2)
Relatedness	111	(24)
Paternity	111	(15)
Weight of evidence for paternity	111	(1)
Prior probabilities	112	(1)
Calculating likelihood ratios	113	(4)
Multiple loci: the effect of linkage	117	(2)
s may be related to c but is not the father	119	(1)
Incest	120	(1)
Mother unavailable	121	(1)
Mutation	122	(4)
Other relatedness between two individuals	126	(3)
Only the two individuals profiled	126	(1)
Profiled individual close relative of target	127	(1)
Profiles of known relatives also available †	128	(1)
Software for relatedness analyses	129	(2)
Inference of ethnicity or phenotype †	131	(2)
Relatedness exercises	133	(2)
Other approaches to weight of evidence	135	(10)
Uniqueness	135	(3)
Analysis	136	(2)
Discussion	138	(1)
Inclusion/exclusion probabilities	138	(3)
Random man	138	(1)
Inclusion probability of a typing system	139	(1)
Case-specific inclusion probability	139	(2)
Hypothesis testing †	141	(2)
Other exercises	143	(2)
Issues for the courtroom	145	(12)
Bayesian reasoning in court	145	(1)
Some fallacies	146	(2)
The prosecutor's fallacy	146	(1)
The defendant's fallacy	147	(1)
The uniqueness fallacy	148	(1)
Some UK appeal cases	148	(6)
Deen (1993)	148	(1)
Dalby (1995)	149	(1)
Adams (1996)	149	(2)
Doheny/Adams (1996)	151	(2)
Watters (2000)	153	(1)
US National Research Council reports	154	(1)
Prosecutor's fallacy exercises	155	(2)
Solutions to exercises	157	(18)
Bibliography	175	(8)
Index	183