Being the night shift security guard, Dero Yermenjian had ample 
opportunity to steal expensive equipment from Prescott Industries. 
On the morning of his death, Cory Matthews stormed into the 
building just before 7:30 and accused Dero of the thefts. In a 
panic, Dero followed Mr. Matthews to the elevator bank and 
bludgeoned him to death. Instead of disposing of the body, he 
dragged Mr. Matthews into the elevator and let the doors shut. 
He immediately went back to his guard's station. 
    Knowing that Amy always took the stairs, Dero quickly 
agreed with Goat when she mistook Amy for Mr. Matthews, 
making it appear that the victim was still alive when he got 
into the elevator. However, if it truly were Mr. Matthews 
instead of Amy, he would have still been waiting for the 
elevator since at that very time, Chris DoHer had already 
summoned the elevator to the third floor. Goat could never 
have had enough time to kill Mr. Matthews and place him in the 
elevator in such a short time after signing in. So it was obvious 
to Detective Cordero that the only one who could have killed 
Mr. Matthews was Dero Yermenjian. 

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