FBI True Season 4 is to Premiere on CBS, Paramount+

Masked shooters attack an office Christmas party in San Bernardino, killing and wounding dozens of people. FBI investigators descend on the scene, looking for clues about the identity of the killers. But as they try to find out who the active shooters are, they're faced with a more urgent question…where are they and do they plan to strike again?

In one of the most infamous serial killer cases in American history, the FBI works with local law enforcement in California to try and apprehend the so-called "Golden State Killer." It's a case that spans four decades, as the killer and rapist continually manages to elude law enforcement. Authorities resort to an unprecedented use of DNA data in an attempt to finally track down the man responsible for 13 murders and 51 sexual assaults.

The FBI learns Timothy McVeigh hopes to instigate a civil war in America with his bombing of the Federal building in Oklahoma City. His arrest will set in motion a nationwide hunt that will take investigators from Oklahoma across the country, questioning collaborators, uncovering evidence and unveiling the history of a young man disillusioned with the government.

An early-morning explosion at a federal building in downtown Oklahoma City kills and injures hundreds. FBI investigators quickly determine that the building has been bombed. The Bureau coordinates a complex rescue mission to save survivors of the blast. At the same time, agents comb through the wreckage, searching for clues about the bomber.

Rumors swirled for years that two former NYPD detectives, Stephen Caracappa and Louis Eppolito were working for the Mafia, committing crimes that included murder, kidnapping and money laundering for their mob bosses. Both men retire from the police department and move to Las Vegas, but when a former Mafia underboss admits that Caracappa and Eppolitto carried out a number of murders on his orders, the FBI formulates a plan to bring the "Mob Cops" to justice.

When an armed bank robber terrorizes the Boston area, the violent holdups leave bank employees and customers fearing for their lives. Without any solid leads, the FBI's Bank Robbery Task Force must use all its resources to catch the perpetrator in the act. But can law enforcement catch up to the Southside Bandit before the situation turns deadly?

Two FBI agents go undercover to infiltrate a dangerous criminal motorcycle gang. The Outlaws – archrivals of the infamous Hells Angels – are running wild in Taunton, Massachusetts, bringing drugs and violence to the formerly peaceful town. The stakes are high as the agents plan a daring takedown. Will they make a big bust or will their cover get blown?

Newburgh NY is a small town with a big problem. Gang warfare has made it the most violent city in the state. Tapping into U.S. military surge strategy, FBI agent James Gagliano hatches a plan to dismantle the rival gangs in one day full of gangster shock and awe.

In the tense hours following the bombings, Sergeant John MacLellan heads out on his night shift. That same evening, an MIT police officer is murdered by two attackers. No one knows yet that the cop killers and the bombers are one and the same, and Sgt. MacLellan comes face to face with the perpetrators. The shootout that ensues leads to a citywide manhunt.

When two bombs cut a swathe of death and destruction through the crowd of runners and spectators at the finish line of the Boston Marathon, the FBI steps up to lead a massive manhunt for the perpetrators. As the nation watches transfixed, the Bureau and its law enforcement partners work against time to find the bombers before they can strike again. When the suspects finally emerge, they lead authorities on a deadly high-stakes chase through the streets of Boston.

The FBI Hostage Rescue Team works with brilliant FBI profiler Molly Amman to extract a five-year-old boy from a bunker built by a heavily armed captor named Jimmy Lee Dykes. The profiler must convince FBI director Robert Muller that negotiations with the erratic Dykes are doomed to fail

In 2013, Jimmy Lee Dykes shoots and kills a rural Alabama school bus driver and takes a five-year-old boy hostage in a carefully constructed bunker. The FBI discovers that the bunker is lined with explosives and Dykes is heavily armed. After a six day standoff, Dykes sets a deadline for the following day to broadcast his grievances on TV news, or he will kill the boy and himself.

An unknown sniper terrorizes the citizens of Washington, D.C. over three weeks in October, 2002. FBI investigators hunt for the murderer as the killings continue. With limited evidence and a series of false leads, the investigation stalls. Will a series of cryptic clues left by the shooter help the authorities end the killing spree?

Notorious Boston mobster Whitey Bulger, accused of 19 murders, has been on the run for 15 years. He went on the lam after being tipped off by a corrupt FBI agent. The Bureau brings in two hard-charging agents from outside the city to track down Bulger. Will their new approach lead to the capture of the FBI's Most Wanted fugitive? 

After a fifty-one day standoff, the FBI decides to move in on the Branch Davidians and their leader, David Koresh. Three agents tell heart wrenching stories about what happened on that historic day and the deadly blaze that ensued.

An ATF raid on the compound of an armed apocalyptic religious group in Waco, Texas turns deadly. After a terrifying shootout, four federal agents are dead and more than a dozen are wounded. The FBI steps in with its tactical and negotiation teams, but as both sides dig in, concerns grow about the intentions of the group's leader and the welfare of the children inside.

After a "family friend" murders a California mother and her 8-year-old son, the woman's 16-year-old daughter is nowhere to be found. Authorities learn the killer has kidnapped Hannah Anderson and taken her to the remote wilderness of Idaho. The FBI's Hostage Rescue Team receives a tip and tries to track down the pair before it's too late. 

On the 11th anniversary of 9/11, armed men storm the U.S. Special Mission in Benghazi, Libya. The attack kills US Ambassador Christopher Stevens and three other Americans. The FBI launches an international investigation to track down the perpetrators, but in the chaos of post-Gaddafi Libya, arresting a suspect is no easy feat. 

In 1999, three women went missing in Yosemite National Park, launching the largest search and rescue operation in US history.  The bodies of two of the women are found in a burned car, and the third is only found when the killer sends a taunting note to the FBI.  Five months later, when a fourth woman is found beheaded near the park, the Bureau believes a serial killer may be on the loose.

On Sept 17th, 2016 a bomb detonates on 23rd Street in the Chelsea neighborhood of Manhattan, injuring over 30 people and causing mayhem. In the following hours and days, multiple bombs are discovered across Manhattan and New Jersey, all homemade devices designed to kill or maim as many people as possible. The FBI works with local law enforcement to track down a suspect who comes to be known as "The Chelsea Bomber," culminating in a nail-biting standoff.