Major Valchek's son-in-law was once an impulsive, frightened officer with terrible street instincts and no clue how to handle police work. But marrying a politically-connected major's daughter has its privileges. Valchek managed to salvage Prez's career when the young officer shot up his own squad car and then called in a Signal 13, claiming to be under fire - as obvious a cry for help as a frightened patrolman can issue. Hoping to resurrect his son-in-law's career, Valchek got him reassigned to the Barksdale, where Prez began as he left off, with terrible instincts and volatile behavior. Held in the office by Daniels, who was unwilling to have Prez on the street, the young plainclothesman began to learn the first lessons of police work from Lester Freamon, and he quickly blossomed - with an ear for wiretaps, a facility with codes, and a gift for chasing down paperwork. He also proved to be honorable and loyal. By the end of the Barksdale and port cases, he became a valued member of the wiretap unit.
Then on a food run in the ghetto, his street instincts surfaced for a final time. Responding to a Signal 13, Prez mistakenly shot and killed a black undercover officer. He was charged administratively with failure to properly identify himself in the racially-charged incident - a charge that he could have deflected if he chose to defend himself. But the incident made Prez reconsider whether he was meant for police work. He resigned and began studying for his teaching certificate. His first year at Tilghman Middle school is an eye opening experience as he encounters administrators who are forced to be concerned with making their statistics and promoting kids whether they're ready or not. He also has to learn how to command respect of his street-savvy charges, and how to be a good teacher without getting too emotionally involved.