The Vitals monitor, found in the Office on Polus and the Security room on Airship, is an extremely powerful tool for Crewmates. It displays the status (alive/dead) of all players in real-time.
When a Crewmate dies, their name will immediately turn red on the Vitals screen. This allows Crewmates to know when a kill occurred, even if they don't know where or who did it. This information can be crucial for narrowing down suspects.
As a Crewmate, check Vitals frequently. If you see a death, immediately consider who was near the Office/Security room and who might have just left. As an Impostor, be aware that Vitals will instantly reveal your kill. Try to kill and vent away quickly, or sabotage Comms to disable Vitals before a kill.