STRAF 2: New features and improvements of the STR population data analysis software.

Population data in forensic genetics must be checked for a variety of statistical parameters before it can be employed for casework. Several tools exist to perform such tasks; however, it can become challenging to obtain the right results due to the number of software to use and the broad range of input formats. Furthermore, a substantial amount of experience is required to use some of these programs. To overcome these difficulties, we have developed STRAF (STR Analysis for Forensics), a convenient online tool to analyse STR data in forensic genetics. Since its first release in 2017, it has been used in many studies to report allele frequencies, forensic and population genetics parameters, and to explore genetic datasets interactively through a user-friendly interface. Herewith, we introduce the latest version of the STRAF software and the improvements we have implemented over the last years. STRAF 2 includes several new features, such as new statistical methods (multidimensional scaling, comparison to a reference population, haplotype diversities and frequencies) and file conversion utilities. Performance and user experience have also been improved and documentation has been extended. This new version is freely available as an R package (https://github.com/agouy/straf) and a web application (https://straf.fr).