There's an achievement for trapping Father Elijah in the vault, but he has a knack for seeing right through stealth regardless of your preparations. Other guides suggest you should be able to just sprint for the compartment in the SE corner of the room, but every time I've tried, he detects me and the blue force fields come back up just before I'd make it through the door.
How do I trap Father Elijah in the vault?
Best Answer
It's tricky to do, and he does tend to find you if you get too far away from the vault before he arrives, but it's doable: