Ultimate Conman?
*Jack laughed, shaking his head.*
Really? Your graspin at straws son. Just cause I use my luck for gamblin don't make me a conman. Sides, the trail leads from your lab, not mine. How's that work?
*Jack draws a card, holding it up to reveal the Jack of Spades.*
Here's my theory. Jin asked Olly to his lab. When he got there, he killed him and dragged his body off to Geoff's lab to try and pin it on him. He intended to remove his name from the letter do it looked like Olly met Geoff in his lab and then was killed. But before he could do it properly, He was found by our first victim found: Leo, prolly tryin to raid Jin's lab again but found the blood trail and followed it. Jin stabbed him on the third floor, but Leo was able to get to the elevator and escape. Jin chased him up to the first floor, not wantin a witness to get away and killed him in the library, havin found him due to Leo leavin a bloody hand print on the door. But, due to this, he was unable to properly clean up. That explains the mess we found.
*Jack puts the Jack of Spades back into his deck randomly before looking back up.*
I think that makes a good theory, don't you? Holes are accepted though. Always like the truth I do.