A Litigator's Guide to DNA: From the Laboratory to the Courtroom Book

Acknowledgments     xi
Introduction     xiii
The Structure of DNA and the Variability of the Human DNA Sequence     1
You Are Out of Your Field, But Not Out of Your Depth     1
Markers, Alleles, Genotypes and Profiles     2
The Two Sources of DNA in Human Cells     5
The Structure of DNA and RNA     6
Variability Is the Rule, Not the Exception     11
Polymorphisms Commonly Used for Forensic Testing     15
Using the DNA Profile to Identify an Unknown Perpetrator     24
References and Additional Readings     25
The Molecular Biological Basis of Forensic DNA Tests     27
Extraction and Quantification of DNA     27
Polymerase Chain Reaction (PCR)-Based Tests     32
Variable Number of Tandem Repeats (VNTR) Testing     50
Direct Sequencing     51
References and Additional Readings     53
Quality Control, Quality Assurance and Sources of Uncertainty in the Data     55
Laboratory Accreditation, Personnel Certification and Proficiency Testing     55
Validation Studies     59
The Inevitable Nemeses: Suboptimal Samples and Human Error     61
Allele Dropout Due to Degradation, Preferential Amplification and StochasticEffects     70
Artifacts Inherent in STR Analyses     75
Hybridization Specificity in Dot-Blot Tests     87
References and Additional Readings     88
Population Genetics, Probability Calculations and the Proper Interpretation of the Evidence     91
The Common Logical Fallacies     91
Databanks and Databases     99
Allele Frequencies, Genotype Probabilities and the Product Rule for Independent Events     106
The Principles of Population Genetics that Impact Forensic DNA Calculations     113
Applying the Product Rule-Compensating for Population Substructure and Possible Allele Dropout     119
The Likelihood Ratio (LR) Allows the Analyst to Compare the Strength of Competing Hypotheses     135
The Application of Bayes' Theorem to Paternity Disputes     142
Recommended Procedure for Analyzing Mixed Samples     147
References and Additional Readings     167
Mitochondrial DNA (mtDNA) Analyses     171
The mtDNA Molecule-Abundant and Durable but Less Variable than nDNA     171
Laboratory Analysis of mtDNA Haplotypes     174
Matrilineal Inheritance and a Lack of Recombination     178
A High Mutation Rate Leads to Mitochondrial Heteroplasmy     180
Statistical Analysis of mtDNA Haplotype Data     187
References and Additional Readings     193
Y Chromosome Analyses     197
Y Chromosome Evolution and its Consequences for Forensic Analyses     197
Laboratory Analysis of Y Chromosome Haplotypes     204
Statistical Analysis of Y Chromosome Haplotypes     207
References and Additional Readings     212
DNA in Court     215
The Evolution of Standards for Admissibility of Experts and Evidence     215
The Ongoing Controversy Regarding Laboratory Error Rates     225
Counsels' Obligations Regarding Discovery     228
Expert Witnesses     232
The Durability of DNA Presents Problems for Statutes of Limitation     237
Rape Shield Laws May Limit the Use of DNA Evidence     238
Judges' and Jurors' Perceptions of DNA Evidence     239
References and Additional Readings     253
Arguing for the Prosecution     255
Obtaining DNA Samples     255
DNA in the Courtroom: The Essentials of the Prosecution's Presentation     279
References and Additional Readings     312
Arguing for the Defense     313
The Defense's Choice of Strategy     313
Elements of a Competent Defense      326
When the Defendant Has Been Identified by a Databank Search     362
References and Additional Readings     367
Postconviction DNA Testing     369
DNA has the Power to Exonerate the Innocent     369
Avenues for Relief     370
There Are Many Procedural Obstacles     373
New Evidence May Justify a New Theory of the Case     379
Accessing the Necessary Samples     380
Know the Specific Provisions of the Controlling Statute     383
References and Additional Readings     386
Using the Chi-Square Test to Determine if a Population Conforms to HWE Expectations     389
How the RMP, Prior Odds of Guilt, and the PFP Influence the Posterior Odds of Guilt (POG)     393
Paternity Index (PI) Calculations for Different Combinations of Maternal, Child and Alleged Father Genotypes     397
A Sample Consent Form to Collect an Oral Swab, Which Allows the Profile Obtained to Be Entered Into a Databank for Use in Additional Investigations     399
Doing Your Own Research: Useful References, Websites and Strategies for Finding Current Information     401
Glossary of Key Terms     411
Index     423