In forensic science, DNA reigns supreme when it comes to identifying individuals. However, some forensic applications cannot rely on DNA genotyping, like identification of the biological origin of a trace that can be crucial to unveil what happened at a crime scene. Also, biological evidence, especially older samples, regularly contains little, damaged or even no DNA. Therefore, mass spectrometry-based (MS) proteomics holds great promise for forensics. MS-based methods can identify pure as well as mixtures of biological matrices from different species without any additional sample consumption, preserving the full trace for DNA extraction. However, with the aim of finding biomarkers, the current state-of-the-art, i.e. data-dependent acquisition (DDA) MS, is confined by its stochastic nature. Therefore, I propose to introduce data-independent acquisition (DIA) MS in forensics. Herein, peptides are continuously fragmented, generating a digital fingerprint of the sample that is both more qualitative and quantitative compared to DDA. Applying our latest innovation, i.e. combining narrow window DIA with in silico predicted spectral libraries, will allow to dig deeper in the proteomes than ever before. Equally important, narrow window DIA is compatible with targeted MS on tandem quadrupole instruments. In conclusion, the in-depth DIA-analysis of forensic samples will provide new biomarkers that can be translated into high throughput multiple reaction monitoring (MRM)-based assays.