Consuela Alvarez is the maid of William Hill and wished William goodnight before he was killed.
At the night of professor William Hill's murder she stops by William's office and wishes William goodnight, unknowing that he was going to be murdered. She somehow managed to witness William's murder at the hand of who appeared to be Abraham Lincoln.
Sam and Dean Winchester find out there was a witness, but the sheriff says she is making no sense at all. The boys head outside where Consuela is, and thanks to Sam's freshman Spanish, he is able to communicate with her. Sam asks her for a description of William's killer, and she tells him it was a tall man with a beard, wearing an old style tall hat. Dean mentions Abraham Lincoln, and Consuela confirms that, President Lincoln killed Mr. Hill. Sam and Dean are reasonably confused.