Judge Daniel Locallo developed his interest in law as a result of hearing stories about what his father, August, experienced in courtrooms. Later, after Locallo graduated from law school, August assisted his son with getting work as a prosecutor. Locallo developed a reputation for being competitive and well-prepared. In 1983, after about six years as a prosecutor, Locallo left the state’s attorney's office to practice labor law for the Teamsters Union; he then moved into personal injury law. In 1986, Locallo applied with 150 other lawyers to fill one of nine vacancies for an associate judge. Locallo achieved his ambition on June 13 of that year, when he was sworn in as a judge at the age of 33. 

Initially, Judge Locallo “handled drunk-driving cases, misdemeanors, and an occasional felony preliminary hearing” (59). Then, Judge Locallo quarreled with an elder colleague and got transferred to “branch courts” where he handled “small matters” (60). 

In 1992, Judge Locallo ran for circuit judge—a better-paying position than that of associate judge—“in a northwest-side subcircuit” (61). He won the election on November 3, 1992. He initially served on 26th Street as a substitute judge until an opening for a permanent spot led to his installment in Courtroom 302 in December 1994.