### Abstract

Language | English |
---|---|

Pages | 212-217 |

Number of pages | 5 |

Journal | Journal of the Forensic Science Society |

Volume | 33 |

Issue number | 4 |

DOIs | |

Publication status | Published - Oct 1993 |

### Fingerprint

### Keywords

- automatic data processing
- bayes theorem
- dna fingerprinting
- homicide
- statistics
- probability

### Cite this

*Journal of the Forensic Science Society*,

*33*(4), 212-217. https://doi.org/10.1016/S0015-7368(93)73017-0

}

*Journal of the Forensic Science Society*, vol. 33, no. 4, pp. 212-217. https://doi.org/10.1016/S0015-7368(93)73017-0

**Statistical interpretation of DNA evidence.** / Gettinby, G.; Peterson, M.; Watson, N.D.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Statistical interpretation of DNA evidence

AU - Gettinby, G.

AU - Peterson, M.

AU - Watson, N.D.

N1 - Continued as Science and Justice. PMID: 8151283

PY - 1993/10

Y1 - 1993/10

N2 - The aim of this research is to assess the effect of recent admixture on the evaluation of DNA evidence. We develop an admixture model based on the distribution of individual admixture proportion in the population and allow us to relax the assumption of ramdom mating. Genetic disequilibrium depends on the variance and other higher moments of the distribution of individual admixture proportion. Although between locus disequilibrium is reduced by a half after each random mating, change in the mating pattern can lead to increase in the disequilibrium. Markov Chain Monte Carlo method is used to estimate important parameters such as population admixture proportions and allele frequencies in the parental populations. This is important especially for analysis of the New Zealand Maori population since allele frequencies for the ancestral population cannot be estimated directly. Simulation showed that the estimation algorithm is robust to the specification of the prior distributions. The gentoype frequency can be evaluated conditional on the individual's family history and the posterior density of observing the genotype at the crime scene can be estimated using importance sampling. This posterior predictive probability is equivalent to the match probability commonly used in forensic casework. We compare the match probability estimated under the admixture model and that under the substructure model using simulation and data from the New Zealand DNA database. Equivalent coancestry coefficient the value of θ which can be used in the substructure match probability to obtain a similar estimate compare to the admixture model, can be estimated. We show that the distribution of equivalent coancestry coefficient can be used to determine a value of θ which can be used to provide conservative estimate of the match probability under both population strucutres.

AB - The aim of this research is to assess the effect of recent admixture on the evaluation of DNA evidence. We develop an admixture model based on the distribution of individual admixture proportion in the population and allow us to relax the assumption of ramdom mating. Genetic disequilibrium depends on the variance and other higher moments of the distribution of individual admixture proportion. Although between locus disequilibrium is reduced by a half after each random mating, change in the mating pattern can lead to increase in the disequilibrium. Markov Chain Monte Carlo method is used to estimate important parameters such as population admixture proportions and allele frequencies in the parental populations. This is important especially for analysis of the New Zealand Maori population since allele frequencies for the ancestral population cannot be estimated directly. Simulation showed that the estimation algorithm is robust to the specification of the prior distributions. The gentoype frequency can be evaluated conditional on the individual's family history and the posterior density of observing the genotype at the crime scene can be estimated using importance sampling. This posterior predictive probability is equivalent to the match probability commonly used in forensic casework. We compare the match probability estimated under the admixture model and that under the substructure model using simulation and data from the New Zealand DNA database. Equivalent coancestry coefficient the value of θ which can be used in the substructure match probability to obtain a similar estimate compare to the admixture model, can be estimated. We show that the distribution of equivalent coancestry coefficient can be used to determine a value of θ which can be used to provide conservative estimate of the match probability under both population strucutres.

KW - automatic data processing

KW - bayes theorem

KW - dna fingerprinting

KW - homicide

KW - statistics

KW - probability

UR - http://www.sciencedirect.com/science/journal/13550306

UR - http://dx.doi.org/10.1016/S0015-7368(93)73017-0

U2 - 10.1016/S0015-7368(93)73017-0

DO - 10.1016/S0015-7368(93)73017-0

M3 - Article

VL - 33

SP - 212

EP - 217

JO - Journal of the Forensic Science Society

T2 - Journal of the Forensic Science Society

JF - Journal of the Forensic Science Society

SN - 0015-7368

IS - 4

ER -