Post-mortem interval (PMI) estimation is still based on empirical analysis of macrodata not always endowed with the reliability required in forensic field. Death promotes tissue decomposition due to biomolecules degradation, especially proteins. In order to improve the accurate PMI estimation, identifying sensitive post-mortem biomarkers, was applied herein for the first time a gel-based proteomics approach on mouse model over post mortem time course. A specific and reproducible evaluation of tissues for thanatochronological purposes is strictly dependent on the condition of biological source, so that tissue handling should be optimized. To this aim, we investigated the proteome changes in cortex samples of 6-weeks old female SAMR1 mice over a post-mortem time course. After death, brain tissue was removed immediately (T0) and after 4, 8, 12, 24 and 32 h, maintaing animals at 4°C. Dissected tissues were frozen at -80C°until processed. Proteomic analysis, performed on sampes related to early and late PMIs (24 h post-mortem, respectively) showed protein level changes as compared to T0 samples, with a remarkable increase in Calpain11 in the early PMI, as well as in Caspases 7 and 8 together Gasdermin 3 in late PMI. These findings were confirmed by LIFT mass spectrometry technology and western blot analysis and, although requiring further investigation in other biological samples, suggest that these proteins could be considered as putative biomarkers of different PMIs. The primary aim was to identify potential new biomarkers useful for PMI assessment as well as additional parameters for sample quality measurements.