Abstract: The present invention relates to a computer-assisted method of analyzing a DNA mixture having two or more individual contributors by use of STR technology. The method comprises the steps of obtaining, for a number of STR loci, observed peak area data vector and observed peak height data vector for each peak within a locus, and observed allele data informing which alleles are observed for each loci; and obtaining peak area model data for peak areas by use of a statistical model assuming a normal distribution for the peak areas and assuming conditional independence of the peak area vectors given the sums of the peak areas within each locus. A conditional mean vector and a conditional covariance matrix is proposed and used for the statistical model.