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Interpreting DNA Mixtures Based on the NRC-II Recommendation 4.1: Tables (Forensic Science Communications, October 2000)

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October 2000 - Volume 2 - Number 4

Interpreting DNA Mixtures Based on the
NRC-II Recommendation 4.1

Table 1
All Possible Genotypes of
Two Unknown Persons and Their Corresponding Probabilities in Computing p2 +cd * abcd ,

CaseGenotypes of
2 unknowns
Probabilities
1 aacd 4( pa Ú pa )( pc Ú pd ) + 8( pa Ú pc )( pa Ú pd )
2 bbcd 4( pb Ú pb )( pc Ú pd ) + 8( pb Ú pc )( pb Ú pd )
3 accd 4( pc Ú pc )( pa Ú pd ) + 8( pa Ú pc )( pc Ú pd )
4 acdd 4( pd Ú pd )( pa Ú pd ) + 8( pa Ú pd )( pc Ú pd )
5 bccd 4( pc Ú pc )( pb Ú pd ) + 8( pb Ú pc )( pc Ú pd )
6 bcdd 4( pd Ú pd )( pb Ú pc ) + 8( pb Ú pd )( pc Ú pd )
7 ccdd 2( pc Ú pc )( pd Ú pd ) + 4( pc Ú pd )2
8 cccd 4( pc Ú pc )( pc Ú pd )
9 cddd 4( pd Ú pd )( pc Ú pd )
10 abcd 24( pa Ú pb )( pc Ú pd )

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Table 2
A Rape Case in Hong Kong

LociEvidence profile (E) and
frequencies (F)
Victim (V) and
suspect (S) profiles
D3S1358 E = {14, 15, 17, 18} V = {15, 18}
F = {0.033, 0.331, 0.239, 0.056} S = {14, 17}
vWA E = {16, 18} V = {18, 18}
F = {0.155, 0.158} S = {16, 16}
FGA E = {20, 24, 25} V = {20, 24}
F = {0.042, 0.166, 0.106} S = {25, 25}

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Table 3
Likelihood Ratios for the Case in Hong Kong
With Two Sets of Hypotheses

Hypothesis qD3S1358vWAFGACombined
S1 0 63.4 13.7 18.1 15,721
0.01 63.4 13.5 17.8 15,235
0.03 63.4 13.0 17.2 14,176
S2 0 285.4 119.0 359.2 12,175,485
0.01 285.4 114.0 349.2 11,339,010
0.03 285.4 104.0 331.2 9,810,840

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Table 4
The Likelihood Ratios for the Simpson Case
With a Three-Allele VNTR Mixed Profile

n*qor 2pm*
012
2 q = 0 1,623 70 3.06
q = 0.01 1,554 70 3.19
q = 0.03 1,431 70 3.46
2p 158 70 31.06
3 q = 0 21,606 938 41.06
q = 0.01 19,427 881 40.06
q = 0.03 15,914 783 38.06
2p 54 24 11.06
4 q = 0 396,495 17,220 748.06
q = 0.01 338,541 15,352 696.06
q = 0.03 251,636 12,373 609.06
2p 68 30 13.06
*The number of unknowns in Hd and Hp are n and m,
respectively.

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