[everyone is focused on Lucina. But it's becoming clear:

She didn't kill Miki. Someone was sitting here, listening to that poor woman spill her guts, and hoping they wouldn't keep looking.

He won't allow that. While everyone is distracted he darts out to the podium where the knife is sitting.

It's understandable if one thought he was going to attack, but instead he jams the pad of his thumb on the tip,
welling up bright red ]

We're not done yet! Marisa said it was blood on the shovel-

[he holds up his bleeding hand for all to see]

We're all from different worlds, and it wasn't Petuu... Lets see who is and isn't red. Let's find our killer.