Petty thief Louis “Lou” Bloom is caught stealing from a Los Angeles construction site by a security guard. He attacks the guard, steals his watch and leaves with stolen material. After selling the material at a scrap yard, Lou asks for a job, but the foreman says he does not hire thieves. While driving home, Lou sees a car crash and pulls over. Stringers—freelance photojournalists—arrive and record two police officers pulling a woman from the burning wreck. One of the stringers, Joe Loder, tells Lou that they sell their footage to local news stations.
Inspired, Lou steals a bicycle and pawns it for a camcorder and a police radio scanner. After two unsuccessful attempts at recording incidents, Lou records the aftermath of a fatal carjacking and sells the footage to KWLA 6. The morning news director, Nina Romina, tells him the station is especially interested in footage of “graphic” accidents and violent crime in affluent, White areas. Lou hires an assistant, Rick, a young hustler desperate for money. To give his footage more impact, Lou tampers with crime scenes: in one case moving a body to get a better camera angle. As Lou’s work gains traction, he buys better equipment and a faster car.
Lou pressures Nina into a date, telling her he knows she is desperate for higher ratings. On their date he threatens to terminate his business with Nina unless she has sex with him, and it is implied that she acquiesces. Lou turns down an offer to work for Joe, but when Joe beats him to an important plane crash story, Nina demands that Lou get better footage and keep his end of their bargain. In retaliation, Lou sabotages Joe’s van; when it crashes, Joe is severely injured and Lou records the aftermath.
Later, Lou and Rick arrive before the police at the site of a triple-homicide home invasion in Granada Hills. Lou records footage of the gunmen leaving in their SUV and of the victims in the house. The news staff fret over the ethics of the footage but Nina is eager to break the story. In exchange, Lou demands public credit and more money. Police detective Frontieri shows up at Lou’s apartment to question him about his connection to the home invasion. He gives her edited footage of the incident, cutting out the parts with the gunmen. That night, Lou and Rick track down the driver to his house, staking out the house until his partner arrives. Lou wants to follow them to a more crowded public area, then call the police and record the ensuing confrontation. Alarmed, Rick demands half the money Lou stands to make, threatening to tell the police about Lou’s withholding of evidence; Lou agrees.
When the gunmen stop at a restaurant, Lou phones the police, warning them that the suspects are armed. They arrive and exchange gunfire. A police officer is shot and one of the killers is gunned down while the other manages to escape in the SUV. The police give chase with Lou and Rick tailing and recording, culminating in a long multiple-car collision. After the gunman’s SUV crashes, Lou approaches the vehicle, claiming that the gunman is dead and urging Rick to film him. The gunman is revealed to be alive as he shoots Rick, flees, and is killed by arriving police officers. As Rick lies dying, Lou films him and tells him that he cannot work with someone who has leverage over him.
Nina is awed by the chase footage and expresses her devotion to Lou. The news team discovers that the home invasion was actually the criminals breaking in to steal cocaine that the homeowners were stashing; Nina refuses to report this information to maximize the story’s impact. Police try to confiscate the footage as evidence but Nina defends her right to withhold it and airs it immediately. Lou voluntarily speaks with Detective Frontieri. While being interrogated by Frontieri, Lou fabricates a story about the men in the SUV following him; Frontieri knows he is lying, but cannot prove it. Later, Lou hires a team of interns to expand his business, telling them he wouldn’t have them do anything he wouldn’t do himself.