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.

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.

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.

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?

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?

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.

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.

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.

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.

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 the aftermath of the bombings of two US embassies in Africa, three FBI agents suspect an injured bystander may well be one of the lead terrorists.

Once the FBI discovers a bomb factory connected to the 1998 attacks on American embassies in Africa, it exposes the vast reach of a little-known terrorist group called Al Qaeda.

FBI undercover agents conduct a sting operation on an ex-con in Boston who has plans to resume his life of crime.

Twelve minutes after its departure from JFK airport, TWA Flight 800 suddenly explodes. FBI investigators must determine if it's a tragic accident or the result of sabotage.

Senator Dianne Wilkerson is beloved by her constituents in Massachusetts, but when the FBI receives a tip that she is accepting bribes, agents from the Public Corruption squad open an investigation.

The FBI investigates the discovery of a dismembered body in Albania and learns a nearly identical crime in Brooklyn 16 years earlier could point them to the killer.

A young man in South Carolina is kidnapped by members of a Mexican cartel and the FBI brings in its Hostage Rescue Team to try and save him.

Pirates murder four Americans off the coast of Somalia and the FBI chases the criminal mastermind across Africa.

The FBI pursues an Al Qaeda terrorist group with plans to bomb the New York subway system.

After one lethal pipe bomb is found inside a Long Island Home Depot, the FBI mobilizes to prevent a potential second bomb from being detonated on Black Friday.

When a would-be terrorist attempts to set off a bomb in Times Square, the FBI embarks on a high-speed, high-stakes race against time to catch the bomber.

Following the murder of a Deputy Sheriff by a Latino gang, the FBI leads a task force in Operation Knockout, the largest anti-gang operation in US history.

Following the fatal shooting of a U.S. Deputy Marshal during a stakeout of a wanted fugitive, the FBI's Hostage Rescue Team is called in.

As the FBI prepares for a final assault on the remote cabin where fugitive Randy Weaver is holed up, a gruesome discovery puts the entire mission on hold.

An FBI investigative specialist with no undercover training goes undercover and comes face-to-face with Robert Hanssen, a suspected spy.

Eric O'Neill, an FBI investigative specialist with no undercover training, manages to win the trust of suspected spy, Robert Hanssen — or so he thinks.

In 2011, 14-year old Chyenne Kircher disappears from her dysfunctional small-town Illinois home, leaving a convincing runaway note.

The FBI doggedly wade through their prime suspect's emotional outbursts, half-truths and outright lies to find out what happened to Chyenne Kircher.

A pipe bomb at a concert is the first of a string of explosions during the 1996 Atlanta Olympics; the FBI have a serial bomber on their hands.

After another deadly bombing, a suspicious character in a wig is seen walking away, sparking one of the biggest manhunts in U.S. history.

After a tip from an informant, FBI agents work to track down priceless works of art stolen from Denmark’s national museum.

In 2015, the FBI uncovered a deep and widespread criminal conspiracy among members of FIFA - including wire fraud, racketeering, and money laundering.

When a massive bomb planted in a van explodes below the North Tower of the World Trade Center in 1993, the FBI sets out to find the bomber

After a family doctor well-known for performing abortions is gunned down in his suburban Buffalo home in 1998, all clues point to an anti-abortion extremist as the sniper.

In 2014, a suburban police detective learns of a Seattle filmmaker who convinces teenage girls to engage in prostitution with fraudulent promises that they'll cash in when he makes a movie on the subject.

When the CIA's most valuable Russian assets start disappearing one by one, the Agency starts hunting for the mole who's been betraying them since 1985.

After the 1963 bombing of a Baptist Church in Birmingham takes the lives of four young girls, the FBI embarks on a four-decades-long quest for justice.

FBI agents uncover new evidence from the Birmingham Church Bombing that could finally bring justice to the young girls killed in this act of racial hatred.

When federal authorities seize a renegade rancher's family cattle in 2014, heavily armed anti-government militias come to his aid and a dangerous showdown ensues.

The FBI faces down a group of anti-government ranchers and heavily-armed militias who've taken over a federal wildlife refuge in Oregon. A car chase through the mountains ensues, and when one rancher refuses to surrender, the showdown turns deadly.

The stabbing death of a wealthy young husband of a beauty queen in Old San Juan leads to a full blown murder-for-fire conspiracy investigation and an international manhunt by the FBI.

Agents uncover the largest oxycodone trafficking operation in American history. But building a case is easier said than done, when the drugs are legal. The FBI zeroes in on twin brother pain clinic owners, suspecting they're running a pill mill.

Days before Christmas, a Pan Am plane crashes in the remote Scottish village of Lockerbie. 290 people are killed, including 190 Americans. The investigation leads the FBI across the world in a quest to find out what caused the unspeakable tragedy.

The FBI gets a tip that the McDonald's Monopoly promo games are rigged, and a mysterious figure dubbed "Uncle Jerry" is behind this scam. There's a race against the clock, as McDonald's agrees to run one more game, hoping to catch him in the act.

The FBI has one shot to catch the McDonald's Monopoly scammers in the act. Agents deploy some very creative undercover techniques to gather evidence. Days away from the takedown, a fax sent to the wrong organization could derail the entire case.

After Bernie Madoff confesses to the FBI that he's responsible for a $64 billion Ponzi scheme he is quickly arrested, but the FBI's job is just beginning. They have the long task of recovering stolen assets to help those whose lives he had shattered.

A small-time crook hoping for a break alerts the FBI to a cadre of corrupt cops within the Boston Police. But taking down three SWAT-trained members of a police force comes with unavoidable risks.

The FBI uncovers a state-sanctioned plot to steal technology that makes U.S. submarines nearly undetectable to enemy sonar - and deploy it in Chinese subs.

It's one of the strangest cases in FBI history. A Pennsylvania pizza delivery driver claims he was delivering an order when a group of men attacked him, put a bomb on him and forced him to rob a bank. Is he an innocent hostage or a co-conspirator?

The case of the Pizza Bomber becomes more complex when the bomb is discovered to be real and explodes. Brian Wells, the pizza delivery man, is dead. Three weeks after the bombing a source tells investigators that there's a dead body in his freezer, right next to the location where Brian delivered pizzas just before he robbed the bank.

Annie Le, a brilliant Yale PhD student, vanishes days before her wedding. Closed-circuit television cameras catch Le entering her research lab but there's no trace of her leaving. The FBI uncovers a dark secret that exposes the shocking truth behind her disappearance.

When fashion designer Gianni Versace is murdered outside of his home, investigators discover a trail of bodies leading to a manhunt for a suspected serial killer. With the suspect on the run, the stakes couldn't be higher for the FBI.

Eight veterans die mysteriously at a VA hospital. After conducting hundreds of interviews, poring over medical charts and electronic records, and exhuming the victims' bodies, the FBI discovers the killer comes from inside the hospital itself.

After eight patients die at a VA Hospital, evidence points to a killer on staff. She was on duty during the deaths; autopsies discover fatal injections of insulin; and evidence reveals a fascination with killing. Now, they must get a confession.

As the FBI's list of missing persons in the Boulder, Colorado, area grows, investigators follow a trail of chilling evidence that unexpectedly leads them to someone within their ranks. What they thought was a valuable asset turns out to be a master manipulator.

After the shocking acquittal of Miami's drug kingpins, authorities suspect that they conspired to infiltrate and obstruct the justice system. Through informants and undercover ops, the FBI uncover a vast web of money, murder, and corruption.

The FBI receives a tip that Sal Magluta's bookkeeper is laundering millions of dollars for the Magluta-Falcon drug organization. When she flees Miami, the FBI uncovers a money laundering scheme that could take down the entire organization.

In 2015, a slew of Denver bank robberies turns deadly when bandits wearing masks from the horror film Scream stab and shove tellers to the ground, empty the vault and then lead police on a high-speed chase that sees two people shot in cold blood.

The Base, a violent white supremacist group, conducts training missions in rural Georgia in preparation for a series of attacks they hope will cause the collapse of American society. In this chilling multi-state, multi-subject case, the FBI must find a way to stop The Base before they set their deadly plans in motion.

With the aid of an undercover agent, the FBI surveils members of The Base as they sacrifice a goat to Odin in rural Georgia. Through a hidden camera and wiretap, FBI agents watch as members assemble a ghost gun and plot a mass shooting in Virginia.

A serial rapist stalks the streets of Scarborough and police call in the FBI. Profiler Gregg McCrary sees a pattern of escalating violence and worries the suspect will resort to murder. When teenage girls turn up dead, his worst fears are confirmed.

A DNA hit links the Scarborough Rapist to murders, exposing a killer couple. The wife claims abuse and testifies, but home videos suggest she's just as guilty. Investigators uncover their dark past, including her sister's death.

A woman withdraws $350,000 from a small-town bank, then passes a note saying she and her husband are being held at gunpoint. The clock is ticking as the FBI and local authorities race to rescue the couple before the kidnappers kill them.

A serial killer is strangling prostitutes across Europe. Austrian police and the FBI profile him, linking the crimes to L.A. He taunts victims' families and vanishes just as authorities close in.

The murder suspect is revealed to be a journalist reporting on his own crimes. He travels to Los Angeles, where more prostitutes are killed. As police close in, he flees to Miami with his girlfriend. U.S. Marshals track him down.

At a casino in Lake Tahoe, a bomb threat leads to a tense FBI mission. Unable to defuse the complex bomb, agents detonate it safely-but it destroys the hotel. As the FBI investigates, they uncover surprising connections to a gambling addict father.

In 2003, a disguised man robs the Xerox Federal Credit Union, killing one and injuring another. The case goes cold until 13 years later, when new DNA testing and a fresh tip bring a breakthrough, leading to a shocking resolution.

In rural Oklahoma, two young girls are found gunned down. After two years with no leads, the FBI profiles the killer, believing the cold-blooded murderer is a local who used two guns to execute the girls-and will likely kill again.

When a woman from a small town in Oklahoma goes missing, state and FBI agents wonder if the suspect in that investigation fits the profile of the killer in the case of two young girls shot dead at the side of a country road - three years earlier.

When a drug dealer reports extortion by a New Orleans police officer, the FBI launches a full-scale investigation into dirty cops. But the sting turns deadly when wiretaps pick up threats to an undercover agent and a cop ordering a hit.

The FBI teams up with Massachusetts State Police to infiltrate, disrupt, and dismantle the extremely violent MS-13 gang network in Greater Boston. They get a break in their case when a recently deported Salvadoran man agrees to become their informant.

The FBI's investigation into MS-13 in Boston is complicated by an informant's unsanctioned crimes.