Abstract: In many situations, particularly in forensic science, there is a need to consider one piece of evidence against one or more other pieces of evidence. For instance, it may be desirable to compare a sample collected from a crime scene with a sample collected from a person, with a view to linking the two by comparing the characteristics of their DNA, particularly by expressing the strength or likelihood of the comparison made, a so called likelihood ratio. The method provides a more accurate or robust method for establishing likelihood ratios through the definitions of the likelihood ratios used and the manner in which the probability distribution functions for use in establishing likelihood ratios are obtained The methods provide due consideration of stutter and/or dropout of alleles in DNA analysis, as well as taking into consideration one or more peak imbalance effects, such as degradation, amplification efficiency, sampling effects and the like.

Abstract: In many situations, particularly in forensic science, there is a need to consider one piece of evidence against one or more other pieces of evidence. For instance, it may be desirable to compare a sample collected from a crime scene with a sample collected from a person, with a view to linking the two by comparing the characteristics of their DNA, particularly by expressing the strength or likelihood of the comparison made, a so called likelihood ratio. The method provides a more accurate or robust method for establishing likelihood ratios through the definitions of the likelihood ratios used and the manner in which the probability distribution functions for use in establishing likelihood ratios are obtained. The methods provide due consideration of stutter and/or dropout of alleles in DNA analysis, as well as taking into consideration one or more peak imbalance effects, such as degradation, amplification efficiency, sampling effects and the like.

Abstract: A computer implemented method of comparing a test sample result set with another sample result set is provided, the method including: providing information for the first result set on the one or more identities detected for a variable characteristic of DNA; providing information for the second result set on the one or more identities detected for a variable characteristic of DNA; and comparing at least a part of the first result set with at least a part of the second result set; and wherein: the comparing includes a likelihood and the likelihood uses a probability density function conditioned on DNA quantity. Further benefits are obtained from the manner in which the probability density function is obtained and/or the use of probability density functions to account for stutter and/or allele dropout.