PATERNITY CALCULATIONS

• Jurisdiction: Australia

PATERNITY CALCULATIONS

Overview ....................................................................................................... [80A.2500]

Paternity trio .................................................................................................. [80A.2520]

Exclusions ..................................................................................................... [80A.2540]

[80A.2500] Overview

Genetic evidence is often used in cases where the relationship between people is in question. Most often, the paternity of a child is in doubt. Similar analysis can assist in the identification of human remains that are believed to be those of a missing person whose spouse and child are available for testing. More generally, the availability of one or more biological relatives can be used to help identify the source human material in situations in which a direct comparison with a known sample of biological material from that person cannot be made.

If the genetic evidence does not exclude the alleged relationship, the weight of the evidence is best evaluated by means of a Likelihood Ratio.

[80A.2520] Paternity trio

The simplest scenario is the mother-child-alleged father trio, in which the alleged father denies paternity, but declines to nominate an alternative father. The identity of the mother is usually assumed, and the alternative propositions are:

1. the alleged father is the true father
2. the alleged father is not the true father.

The weight of the evidence is usually assessed by assuming that the unknown true father is equivalent to a man chosen at random from the population. (The statistical analysis can be altered to accommodate the alternative proposition that the true father is not the alleged father, but a specific relative who is not available for testing.) Let:

X = child's genotype

F = alleged father's...