At some point in almost every movie set in the world of journalism, someone drops a big speech about the Truth. “Nothing’s riding on this,” an editor growls at Woodward and Bernstein in the film “All the President’s Men” amid the horror-flick gloom, “except the First Amendment of the Constitution, freedom of the press and maybe the future of the country.” The rare exception to this big speech rule may be “His Girl Friday,” the greatest movie ever set in a newsroom, which ditched sanctimony for the syncopated report of wits firing at each other like Tommy guns.

The big speech in “Kill the Messenger,” a likable if formulaically pulse-pounding fiction about a real investigative reporter, Gary Webb, arrives near the end. By then, Gary (Jeremy Renner, affable and on cruise control), has tramped, in victory and defeat, through his newspaper, The San Jose Mercury News, and parachuted in and out of danger while chasing a name-making story. It’s the mid-1990s. Mobile phones are as big as clown shoes, and a cutie named Monica Lewinsky has been working in the White House. Gary should be riding high after reporting a series, “Dark Alliance,” linking the Central Intelligence Agency with Nicaraguan contras and the wildfire-like spread of crack through black neighborhoods in Los Angeles. Instead, he sounds and looks haunted or maybe hunted.

Written by Peter Landesman, “Kill the Messenger” is based on a book by Nick Schou about Mr. Webb, his rise and fall, and Mr. Webb’s own book, “Dark Alliance,” his 1998 follow-up to his much-heralded, much-contested 1996 Mercury News series. The film tracks Gary as he reports the story, opening soon after a slinky number, Coral Baca (Paz Vega), hands him a Pandora’s box of a tip. Baca points Gary in the direction of Danilo Blandon (Yul Vazquez), a Nicaraguan drug smuggler and contra supporter who supplies product to a Los Angeles dealer, Ricky Ross (Michael Kenneth Williams). Suddenly, Gary is at a foreign prison visiting another shadowy power player, Norwin Meneses (Andy Garcia), who swans around the yard in a straw hat twirling a golf club.

The director Michael Cuesta started as an independent filmmaker (his credits include“L.I.E.”) but, like many other indies, also works in television. He directed the pilot of “Homeland” (he’s one of its executive producers) and helped establish its insinuatingly intimate, often claustrophobic feel and nervous rhythms, partly through its hand-held camerawork. The look that Mr. Cuesta and his director of photography, Sean Bobbitt, give “Kill the Messenger” at times evokes “Homeland,” but the movie’s cinematography isn’t as frenetic and self-consciously raw, and there’s less bobbing and weaving. Even so, the visual choices in the movie, including all the close-ups of Gary’s face as it lightens and darkens, help create the sense that something deeply personal is at stake.

Mr. Cuesta does his best work in the early scenes of Gary’s sleuthing, which develop a nice, agitated pulse. And because Gary’s dawning awareness of the story’s magnitude mirrors your experience as a moviegoer (you figure it out together), and because Mr. Cuesta keeps you close at Gary’s side, you feel invested in his fate. But the film falters as the story swells and churns, and real people like Representative Maxine Waters of California enter the fray in clips alongside fictionalized scenes meant to look like documentary footage. Gary’s story comes under attack, including from big media types, and he enters a downward spiral as so, too, does the film. There are high-horse speeches, long goodbyes, enveloping sadness, a sense of doom; mostly, there is a journalist betrayed by many factors, including his own calling.