Judge Joe Rifkind, a liberal judge whose nickname is ""Let-Em-Go-Joe,"" releases a petty offender who jumped a subway turnstile. The decision starts a chain of events that end a rookie cop's life, and possibly the judge's career. Standing by Rifkind are his wife, Sarah, and his friend and colleague, Judge Attallah Sims. Sims has a firmer view of justice than Rifkind; her nickname is ""Attallah-the-Hun."" Meanwhile, Assistant District Attorneys Bobby Esposito and Cynthia Bennington are getting to know each other. Cynthia is uptown money. Bobby's Brooklyn, working class roots could demolish his success when his father asks him to erase one of his brother's drug convictions to save him from life in prison.

A teenager is cajoled by a friend to rob a convenience store for kicks, but when the friend pulls a gun on the store's owner, everything takes a turn for the worst. Once arrested, the friend claims he wasn't the one with the gun, and the innocent teen is charged with robbery in the first degree. Legal Aid Attorney Ramon Rodriguez mishandles the case because he was having a tryst with an assistant district attorney and didn't have time to prepare. He puts both the teenager's life and his marriage to Cassandra in jeopardy. Meanwhile, Bobby and Cynthia reconcile.

Bobby and Cynthia's relationship intensifies, but Bobby's career still hangs in the balance as a detective tries to identify and then get information from his hospitalized brother, Frank. Frank has come out of a coma after a drug-related mugging and beating. The detective wants to know who erased a conviction on Frank's drug arrest record. Frank faces either an extra-long prison sentence or turning his brother in for helping him. Also, a veteran cop and his wife attempt to get professional help for their broken marriage after an incident in Judge Sims' night court.

Cynthia sees how the other half lives when a former maid's daughter and childhood playmate, Amanda, appears in night court. Amanda suffers from a bipolar disorder and currently doesn't have her medication and is living on the streets. When Cynthia tries to help Amanda get shelter and a Medicaid card, she's sent on a journey that has her navigating a social services system fraught with red tape. Cynthia, who was raised a millionaire, finds herself in check-cashing lines trying to pay a phone bill and in a hardware store bartering for an air conditioner for Amanda's mother.

Everyone must play along when a Vietnamese man tries to obtain justice for the murder of his parents by American soldiers in the Vietnam War. Judge Sims' courtroom is televised live for the country as Bobby prosecutes and Ramon defends the soldiers who have been forced to come to the court either in person or by telephone. Waiting in the wings are Cynthia and Fatima who can't seem to get along because of Cynthia's privileged background and Fatima's Brooklyn working-class roots.

A woman is arrested after her five-year-old daughter who suffers from cerebral palsy is rushed to the hospital in critical condition. The child is severely underweight and small for her age. The woman has three other children, all by different fathers, who also appear to have been neglected. They are put in foster care while their mother awaits trial. At first, Cynthia, who's prosecuting, wants the woman to get the full punishment and Ramon, who's defending, feels that Cynthia doesn't understand the woman's plight. But both of their opinions will change as the investigation heats up.

Judge Rifkind, who's still being berated in the New York press for going easy on an offender who shot a rookie cop, recommends that Ramon get a taste of what the streets are really like by riding around with other police officers in a patrol car. Ramon complies and meets a prostitute named Paris who was in the wrong place at the wrong time. When Paris appears in night court, Ramon tries to defend her against a prosecuting attorney who has his own agenda. Also, ADA Fatima Kelly is faced with a moral dilemma when she learns that her next door neighbour's daughter is on drugs.

District Attorney Spiegelman singles Bobby out to do pre-trial work for a highly publicized case involving a white cop who shot a black man in the back while arresting him. Bobby is given an assistant with a chip on his shoulder, Milton Hong, who thinks the case should have been his. Bobby re-interviews Hong's witnesses and by gaining their trust, gleans more information from them. Despite all of the evidence he uncovers, it will be another gunshot that brings Bobby to the truth. Meanwhile, Judge Rifkind and his wife, Sarah, go to an alumni weekend in the country where Rifkind is offered a teaching position at the law school.

When the mayor's lead in the upcoming primary begins to wane, the press sites Judge Rifkind's ordeal as one of the Mayor's problems. The mayor puts in motion a plan to have Rifkind removed from the bench. In the ADA's office, maintenance removes Bobby's computer so it can be evaluated for misconduct and Cynthia is called into District Attorney Spiegelman's office. Spiegelman wants her to testify against Judge Rifkind for sexual harassment. He claims someone witnessed a harassing remark Rifkind made to her. She denies anything ever happened but is forced to reconsider when threatened that her testimony will keep Bobby out of jail. Meanwhile, Judge Attallah Sims has her own plan for helping Rifkind.

Shortly after a phone worker reports that he found a ""bug"" on a phone line, the man is arrested on drug charges. He claims that he's being framed by a federal agency to protect an illegal wiretap. His defending attorney, Ramon, believes him and uses it as his defence before Judge Rifkind. Rifkind becomes embroiled in the case, and his paranoia about being monitored escalates when he brings in a friend from Washington to investigate. Judge Sims suffers retribution for going against the mayor to help Rifkind when her personal life is out to the public by the press.

Judge Rifkind seriously considers teaching law school when he revisits his love and appreciation for American law. Cassandra gives Ramon an ultimatum: either he can be a good husband and father, or he can be single. His decision becomes complicated when a former girlfriend makes him an offer that could jump-start more than his career. Bobby prosecutes an abusive husband and his wife for stabbing a police officer. The husband is using his money and influence to put his wife in jail. But the case is the least of Bobby's worries when he's finally faced with his punishment for erasing a conviction on his brother's arrest record.

In the season finale of 100 Centre Street, justice takes a side step when a popular football player is brought into night court for beating up a female groupie. Cynthia attempts to prosecute, but the victim is unwilling to talk and the presiding judge is a fan of the player.

Television executives offer Judge Sims her own show. Cynthia and Bobby contemplate opening a legal aid office for people who don't have money for representation; Bobby would investigate and Cynthia would defend.

Penelope returns to Judge Sims and Rifkind makes his decision about whether he should teach law or stay on the bench.