WARNING! This article contains SPOILERS for Dexter: Original Sin season 1, episode 1!Dexter Morgan keeping trophies was an important part of his serial killing process in the original series, but Dexter: Original Sin changes the context of when he started taking them – and what he would keep. Throughout Dexter’s original eight seasons, the titular vigilante killer kept trophies in the form of blood slides, which he had easy access to as a blood spatter analyst at Miami Metro PD. For every person Dexter killed, he would cut their cheek, take a drop of their blood, place it in a slide, and keep them stored in a box hidden behind his AC unit.

https://screenrant.com/dexter-original-sin-earrings-first-kill-trophy-retcon-explainer/