The ambitious and energetic Rivera became a full-time reporter shortly thereafter, and he shocked New Yorkers with his first cause celebre, a 1972 expose of the heinous conditions at the Willowbrook State School, a facility for the care of the mentally retarded. Securing the Zapruder film for its initial TV presentation brought him his first national scoop, and the charismatic Rivera logged considerable on-camera time for the ABC newsmagazines "Good Night, America", "Good Morning, America" and "20/20". Though his crusading approach to TV journalism recalled his earlier activism, he did not escape criticism for what many perceived as an increasingly egotistical and abrasive manner. Some resented his political stances on various issues, while others felt that his flashy, angry style needlessly sensationalized his reporting. "There's no subject ... that Rivera can't trivialize with his tactics" snapped Howard Rosenberg of the Los Angeles Times. Things eventually came to a head, and Roone Arledge dismissed him from ABC in 1985.

One of Rivera's first attempts to take charge of his career in the mid-80s proved a major misfire. The eager beaver reporter ringmastered the unveiling of a famous mobster's inner sanctum, but "The Mystery of Al Capone's Vaults" (1986), though not a ratings bust with a 31.8 share, was certainly an embarrassment when the expected stash of money, firearms or aged bootleg liquor failed to materialize. Still, the pioneering Rivera went on to do eight more syndicated two-hour primetime documentaries. He made a triumphal entry into the ranks of daytime talk shows with his syndicated "Geraldo!", tweaking the genre with programs devoted to "Exploring Satan's Black Market", "Sexual Secrets...To Tell or Not to Tell" and "Wanted: Elvis! Dead or Alive". Rivera had seemingly found the appropriate media format for his heady combination of journalistic skullduggery and glitzy stylistics, but the fiasco of him brawling with neo-Nazis on a 1988 show is a negative that haunts him to this day.

Though "Rivera Live" (1994- ) debuted in primetime on CNBC several months before the murder of Nicole Brown Simpson, Rivera would make inroads back to a respectability forfeited by his post-ABC hijinks with his extensive coverage of the O.J. Simpson affair. His Juice-bashing worked as journalism, as entertainment, as spectacle. "Rivera Live", with its emphasis on legal issues, reminded the audience he was an attorney, an analytical, educated person, and showed him at his very best, in command of thousands of facts, debating articulate people who actually disagreed with him. Taking his cue from his CNBC demeanor, he cleaned up his daytime act in 1996, abandoning "My sister is a teen slut and I want to be one too" format to carve out his little piece of high ground as America's Investigator. Rivera brought his horn-rimmed glasses and seriousness from his nighttime venture to the renamed "The Geraldo Rivera Show", which began offering substantial journalism that examined "tough social issues" on a regular, if not daily, basis.

In keeping with his penchant for responsible reporting, Rivera traded in his syndicated talk show for a bigger role in the NBC news division, signing a three-year deal worth an estimated $3 million annually near the end of 1997. The terms of the contract called for the continuation of "Rivera Live", an additional CNBC primetime program to be developed by Rivera, four primetime programs to be produced by NBC News featuring the journalist and focusing on legal and criminal justice issues, plus his continued legal commentary on "Today". Despite concerns about Rivera's talk-show host image, NBC, reluctant to lose any "star power" to their fledgling competitor, exercised its right to negotiate the deal after he had already accepted an offer to be an anchor on the Fox News Channel. The demise of "The Geraldo Rivera Show" at the conclusion of its 11th season in August of 1998 marked the end of an era in daytime TV and reinforced Rivera's image as a reborn "serious" journalist.