Abstract: A method of investigation a sample is provided, the sample being a mixture of DNA arising from more than one source. The method includes analysing the sample to obtain a genotype for the DNA present in the sample and assigning a prior probability distribution to the genotype. The likelihood function is considered and a posterior probability distribution for the genotype is established. In this way a probabilistic assessment of the genotype of the major or minor contributor to the sample can be obtained. This is beneficial over prior methods which use a deterministic method, and so involve the use of rule based methods.

Abstract: Methods for establishing the genotype of a DNA sample, and methods for investigating the potential sources of a DNA sample arising from a plurality of source, are provided, the methods being based on a method including: analysing the sample to produce a data profile for the sample for a locus; proposing a suggested genotype; generating a first stage profile for the locus for the suggested genotype; adjusting the first stage profile to account for one or more factors to give a simulation profile; and comparing the data profile and the simulation profile to provide an indication of the likelihood of the data profile given the suggested genotype. The methods in effect make adjustments to take the first stage profile, potentially through one or more intervening profiles, to the simulation profile, the simulation profile being an anticipation of the data profile which would be expected to occur for that suggested genotype in practice.

Abstract: A method of investigation a sample is provided, the sample being a mixture of DNA arising from more than one source. The method includes analysing the sample to obtain a genotype for the DNA present in the sample and assigning a prior probability distribution to the genotype. The likelihood function is considered and a posterior probability distribution for the genotype is established. In this way a probabilistic assessment of the genotype of the major or minor contributor to the sample can be obtained. This is beneficial over prior methods which use a deterministic method, and so involve the use of rule based methods.

Abstract: Methods for establishing the genotype of a DNA sample, and methods for investigating the potential sources of a DNA sample arising from a plurality of source, are provided, the methods being based on a method including: analysing the sample to produce a data profile for the sample for a locus; proposing a suggested genotype; generating a first stage profile for the locus for the suggested genotype; adjusting the first stage profile to account for one or more factors to give a simulation profile; and comparing the data profile and the simulation profile to provide an indication of the likelihood of the data profile given the suggested genotype. The methods in effect make adjustments to take the first stage profile, potentially through one or more intervening profiles, to the simulation profile, the simulation profile being an anticipation of the data profile which would be expected to occur for that suggested genotype in practice.