"From the temples high Of Man's ear and eye..." translates to the tower at the Los Angeles Public Library. Phelps then embarks on a climbing expedition. Once at the top of the tower, the B.D. Killer's next clue can be found in the far corner of the roof. Phelps finds Antonia Maldonado's "Our Lady of Guadalupe" medallion and a fourth excerpt. After a cut scene with Galloway, Phelps needs to decipher the fourth excerpt.
this answer was copied from the wiki. http://lanoire.wikia.com/wiki/The_Quarter_Moon_Murders#Third_Excerpt