A worker at the pergium mining colony on Janus VI who was posted as a lone sentry in the lower levels in 2267 and burned to death by the Horta.
Schmitter appears in the opening scene of The Devil in the Dark. Some fifty miners have already been killed by an unseen creature in the tunnels of Janus VI, and the colony's chief, Vanderberg, is stationing armed guards at key points until the Enterprise arrives.
Schmitter is left by himself to watch a junction on a deep level, phaser in hand and plainly nervous. Vanderberg and Ed Appel have barely walked away when they hear him scream. They run back to find nothing left but a charred patch on the floor.
His death opens the story and shows the way the creature kills, with a corrosive acid that eats through flesh and rock alike. Only later does Spock learn that the Horta was defending her eggs. Schmitter was played by Biff Elliot.