Norman Shepard is the other Bartok scientist tasked with raising the young Martin after Veronica Quaife's death. Whereas his colleague Jainway is antagonistic and sarcastic, Shepard is dour and humorless. When Martin was a child, he often loved grabbing Shepard's tie and pulling him around by it, and Shepard would play along.
Now, though, Martin is all grown up. And incubating in a giant cocoon.
Returning to the lab late one night, Shepard finds Martin's cocoon open and empty and Dr. Jainway very dead. He runs out, bumping into Scorby and another guard on the way. He pauses long enough to babble at them that Martin is out and Jainway is dead before resuming his flight.
Unfortunately for Shepard, the place he chooses to run to is exactly where Martin is. Still quite mad at being lied to, kidnapped and experimented on, Martin, now a seven-foot tall spiny fly creature with four arms, is less than forgiving to the poor Dr. Shepard.
He seizes Shepard by the tie the way he used to do as a (human) child, only this time he isn't being playful. He uses it as a noose and lifts Shepard off his feet with it, hanging him. But Martin isn't done with Dr. Shepard yet. Later, intending to get into Bay 17 to get at the treacherous Bartok, Martin drags Shepard's corpse around by the tie and attempts to gain entry by humorously pushing the body against the card reader in an effort to get it to register Shepard's holographic ID card clipped to his lapel.
However, Bartok is wise to Martin's shenanigans by this point, and locks down the lab, rendering Shepard's ID card useless. The final indignity for the deceased Shepard comes when security guard Mackenzie stumbles upon Martin still jamming the corpse up against the card reader, and Martin uses Shepard as a blunt object to fling at the surprised guard.