Solving the two-decades-old murder case through joint application of ZooMS and ancient DNA approaches.

Bones are one of the most common biological types of evidence in forensic cases. Discriminating human bones from irrelevant species is important for the identification of victims; however, the highly degraded bones could be undiagnostic morphologically and difficult to analyze with standard DNA profiling approaches. The same challenge also exists in archaeological studies. Here, we present an initial study of an analytical strategy that involves zooarchaeology by mass spectrometry (ZooMS) and ancient DNA methods. Through the combined strategy, we managed to identify the only biological evidence of a two-decades-old murder case - a small piece of human bone out of 19 bone fragments - and confirmed the kinship between the victim and the putative parents through joint application of next-generation sequencing (NGS) and Sanger sequencing methods. ZooMS effectively screened out the target human bone while ancient DNA methods improve the DNA yields. The combined strategy in this case outperforms the standard DNA profiling approach with shorter time, less cost, as well as higher reliability for the genetic identification results. HIGHLIGHTS: • The first application of zooarchaeology by mass spectrometry technique in the forensic case for screening out human bones from bone fragment mixtures. • Application of ancient DNA technique to recover the highly degraded DNA sequence from the challenging sample that failed standard DNA profiling approaches. • A fast, sensitive, and low-cost strategy that combines the strengths of protein analysis and DNA analysis for kinship identification in forensic research.