Professor Pico was one of the most highly sort after mathematicians in Florence, highly skilled with numbers, codes and puzzles. "A man without equal in the world of equations". He was hired by Piero de Medici to privately tutor his son, Lorenzo, at home. He was also a member of the sinister Luminari - the secret society intent on stealing Leonardo da Vinci's designs and ultimately bring down the Duke of Florence from power.
Biography
Professor Pico was a highly skilled mathematician who's ability to solve puzzles was much sought after. So much so, he was recruited by the Luminari to assist them in their struggle to gain power. He was also hired to tutor the young Lorenzo de Medici privately. Whether this was a ruse to keep him close to Piero is purely speculative. He was never married and had no family. He lived alone and it was often heard said that "maths are his mistress".
After receiving Leonardo's stolen Note Book, he was given a limited amount of time to decipher the cryptic codes within. After trying several different methods, he was still unable to reveal any of the books secrets. As a final resort he tricked Leonardo into helping him by telling him that his "family" had been threatened by the Luminari and that they would be killed if he did not succeed. Leo agreed to help but on hearing a flaw in his family's names, realises it must be a trap and gives him the wrong code.
Thinking that he had the right code, Pico planned to kill Leo with a Musket. Leo, saved by Mac, escaped out into the city leaving Pico to explain to Piero that he could not decode the plans. Piero dismisses him and sends Caporaso to go after him, following him into the catacombs. He is presumably killed since he is not seen again.
Piero later explains to his son, Lorenzo, that Pico had left Florence on unexpected business and would not be coming back. (Da Vinci's Code)
Personality
Pico was smart and thought highly of himself because of this. However he is quite cowardly as he is easily threatened by Piero. He is treacherous as he betrays and tries to shoot Leo for his own gain.