Getting the conclusive lead with investigative genetic genealogy – A successful case study of a 16 year old double murder in Sweden

On the morning of October 19, 2004, an eight-year-old boy and a 56-year-old woman were stabbed to death on open street in city Linköping, Sweden. The perpetrator left his DNA at crime scene, after 15 years various investigation efforts, including more than 9000 interrogations mass screening 6000 men, there still no clues about identity unknown murderer. successful application investigative genetic genealogy (IGG) US raised interest for this tool within Swedish Police Authority. After legal consultations it was decided that IGG could be applied double murder case as pilot study. From extensive analysis, whole-genome sequencing genotype imputation, data sets established searched both GEDmatch FamilyTree databases. A number fairly distant relatives found from which family trees created. work resulted two candidates, brothers, one whom matched scene samples by routine STR profiling. suspect confessed murders initial police hearing later convicted murders. In paper we describe emerging technology. We disclose details analyses which, due poor quality low quantity DNA, required reiterative imputation efforts. exemplifies its applicability not only but also Europe. pressure is now high involved authorities establish cold criminal investigations missing person identifications. There is, however, continuous need accommodate legal, social ethical aspects well.