The male-specific, human Y-chromosomal short tandem repeats (Y-STRs) are very useful in forensic analysis and human evolution studies. The authors report two sexual crime cases in which the perpetrators were successfully traced using Y-haplotype screening of local patrilineages followed by autosomal STR typing. First, several main local patrilineages from local cases were investigated using Y-STR haplotyping, aimed to find the pedigrees whose haplotypes were identical or similar to those of the crime scene samples. Then, several key suspects were defined from the screened pedigrees, and autosomal STR typing was performed to identify the perpetrator of the crime. The application of Y-haplotype screening of local patrilineages followed by autosomal STR typing in these two cases demonstrates its usefulness for solving sexually related crimes in certain populations. (Published Abstract)