A series of brutal bank robberies and murders led to an exhaustive eight-month investigation by the FBI. What followed was the bloodiest firefight in FBI history.

In the 1980s, gangs ruled the streets of Chicago. Led by Jeff Fort, the dangerous, power-hungry El Rukn gang attempted to conspire with Libya to perform acts of domestic terrorism for money.

On July 4, 1987, seven inmates broke out of a high-security prison in New Mexico. Murderer William Wayne Gilbert orchestrated the escape. In a manhunt, authorities and scientists used the Bureau’s crime laboratory to catch these dangerous criminals.

In 1980, a maid discovered that a copy machine, placed in a busy Las Vegas casino, was actually a bomb. Agents and bomb experts were called in to disarm the deadly device and stop the dangerous extortionist who built it.

A young woman was snatched from her home on a bright spring morning. After several days of searching, a former FBI profiler narrowed the suspect list to one.

A multiple murder-for-hire plot that was meticulously planned and executed. A mother, her 8-year-old son, and a live-in nurse were brutally murdered by an assassin. the FBI was able to zero in on Larry Horn, the father of the 8-year-old.

A wealthy Mississippi woman disappeared from her home in broad daylight. Left behind was a mysterious ransom note listing twelve names and no specific instructions. FBI and local police struggled to find answers in the cryptic message so they could find the kidnapper and retrieve the victim before her time ran out.

After abducting and assaulting a girl at a bus stop, Maghfoor Mansoor was on the run from police and the FBI. From Vegas to Atlantic City, Mansoor left a trail of theft and violence until he was cornered in a hotel lobby.

When an 80-year-old woman is found barely conscious next to the body of her murdered son in an abandoned van, the FBI was brought in and linked the crime to a teenager and middle-aged man.

An Indiana town was turned inside out when an officer was gunned down at point-blank range. A psychotic killer led investigators across the Midwest.

By December 1985, John Gotti had assumed his place as the new Don of the Gambino crime family in New York with the assassination of his boss, Paul Castellano. When the FBI convinced Gotti's underboss, Salvatore Gravano , to testify against him, the jury came back with their verdict: guilty on all counts, including the murder of Castellano.

When notorious bank robber Byron Chubbuck escaped from New Mexico State Penitentiary in 2000, he almost immediately began stealing again. Though he claimed the stolen loot went to the poor, it was clear to the FBI Chubbuck was no folk hero.

A 12-year-old girl is abducted from her home. Scores of police officers and FBI agents determined to find the young girl before it is too late.

Street gangs in Washington D.C. enforced their territories with lethal violence. Authorities vowed to bring the entire gang to justice while the gang leader had fled to Africa.

The hunt for serial killer Angel Resendiz, also known as the "Railroad Killer."

The 1997 Los Angeles Dunbar Armored robbery, the largest cash heist in United States history. Six masked robbers stole $18.9 million.

On February 26, 1993, an explosion rocked the World Trade Center parking garage. Six people died and more than a thousand were injured in the bomb blast which tore a 5-story crater in the building. Mohammed Salameh, Nidal Ayyad, Mahmud Abouhalima, Ahmad Ajaj, Ramzi Yousef and Eyad Ismoil were convicted and will spend the rest of their lives in prison.

The reputed boss of the Genovese crime family, Vince Gigante wandered the streets of New York wearing only pajamas and a bathrobe, but the FBI was convinced he was anything but crazy. The FBI helped convict Gigante of murder and murder conspiracy.

Posing as a fashion photographer, serial killer Christopher Wilder lured young women from shopping malls with promises of fame and fortune. Most ended up dead. national publicity that the FBI created led to the capture of the suspect.

Masked bandits pulled off a daring mid-day bank robbery. With no evidence leaving behind, the FBI forced their own luck.

The bodies of several women began turning up in and around the city of Vienna, Austria. Viennese police turned to the FBI for help.

A young boy and his mother are kidnapped and murdered by a drug cartel.

A teenage immigrant came to U.S. to realize her dream of becoming a doctor, but she found herself an innocent victim of the drug trade. While she was kidnapped, The FBI and local police determined to save the teenager’s life.

A couple engaged in a gruesome crime spree that spanned six states and left eight people dead-including children.

A special task force was formed in the 1990s to combat the flow of Colombia cocaine into New York ports. As part of an elaborate sting operation, one detective went undercover and infiltrated a drug gang connected to Pablo Escobar’s Medellin cartel.

In the spring of 1997, a killer preyed on senior citizens in the quiet town of River Parish, Louisiana. Victims were robbed, beaten, shot and left for dead. FBI agents soon connected the violent crimes to an area mechanic with a gambling problem.

He was a recluse who spread terror through the mail for 18 years. Two men died and more than a dozen were injured , but Ted Kaczynski wasn't known as the Unabomber until his brother tipped off the FBI. Kaczynski's Manifesto, published in major newspapers, set off a flurry of activity for the FBI: writing analysis and comparisons, DNA gleaned from a single postage stamp and finally, Kaczynski's arrest at his tiny cabin. The agents collected enough evidence, including the Manifesto itself, to convict Kaczynski. He is serving four life sentences plus 30 years with no chance of parole.

Lured by the easy wealth of the narcotics industry, crooked cops in the New Orleans Police Department began breaking the laws they were sworn to uphold in the early 1990s.

The decapitation of a young African-American male led the Miami-Dade PD and the FBI along a trail of murder. Investigators quickly discovered that the victim was a dissident member of a religious sect headed by a man calling himself Yahweh ben Yahweh, or God, Son of God.

Polly Klaas was kidnapped from her own slumber party and murdered, lasers helped the FBI identify and find the perpetrator. It took 200 FBI agents two months to find Richard Allen Davis, who was convicted and sentenced to death.

Glendale, Arizona mall, local authorities and the FBI scrambled to recover its cargo of nearly a million dollars.

The bodies of several young women began turning up in shallow graves in the Alaskan wilderness. FBI profilers mapped the criminal's mind.

Agents search for a young girl who was kidnapped while on a family camping trip, and hope the culprit's repeated calls to the child's mother can lead them to an arrest.

Two transported prisoners fleed from a sheriff's department.They moved from state to state in a wave of abduction and car theft. Now the FBI agents believed believed the pair were growing more violent and more victims would cross their path.

Florida’s cocaine imports were among the highest in the nation int the late 80's. Regional territories were enforced with intimidation and murder. Through the combined efforts of the police, the DEA, and the FBI, authorities brought an end to the violence.

The body of an unidentified young woman turned up on a highway in a small Pennsylvania town. Agents persisted to identity the body and to find the killer.

In the 1980s, an illegal drug operation known as the “K Street Crew” opened its doors in Washington, DC. Leader Vincent Hill ran the organization without mercy. The FBI created a task force to put an end to their deadly dealings.

In 1992, a Washington, DC professor was shot and killed as she tried to get into her car, the latest incident in a series of violent carjackings. One week later, a man robbed a bank and security cameras captured the same vehicle as the getaway car.

In 1994, a rash of home invasions plagued the Detroit area. Each time, masked men disguised as police officers broke in with assault rifles and stole money and jewelry. But when one homeowner shot back, the identity of the intruders was revealed.

In 1997, two men used a sledgehammer to break into a Camden, NJ, home. Police tracked the suspects to a nearby park but the criminals were able to escape after a shootout. When new clues emerged, the FBI was called in to locate the suspects.

Three men murder an innocent man as part of an initiation into a Cleveland Ohio biker gang.

After an Arkansas State Trooper is shot and killed, officers catch the murderer and find weapons and explosives in the man’s vehicle. Testing of the weapons leads them to a stand-off with a racist, anti-Semitic paramilitary group.

Marine Captain Shirley Russell disappeared. FBI agents found her husband, himself a former Marine, was acting strangely. The FBI's intense investigation revealed a violent past.

The 1992 kidnapping and murder of Martha Doe Roberts.

A U.S. Customs official disappears from his post near a Texas border crossing. The following day, the Customs official was found dead. Local police and the FBI continued searching for the suspects.

In 1993, a robber surprised unsuspecting customers by dropping through the roof of a California bank. A local resident led police and FBI agents to the perpetrator. However, they learned that he had also masterminded a kidnapping – and had a hostage.

A marine salvager found the bodies of three drug dealers floating in a river. FBI agents suspected that a group of cops might be involved in illegal drug busts.

In 1985, a Lebanese terrorist and his accomplices hijacked Royal Jordanian Flight 405 in Beirut. Several Americans were on board. The FBI worked with other agencies to form Operation Goldenrod, a task force to bring the mastermind to justice.

In the season 3 finale, Drug gangs terrorized Harlem, New York neighborhoods. After a 10-year-old boy became a victim, the FBI formed a task force called C-11, designed to dismantle the gangs.

In 1988, a criminal confessed that two prominent community members hired him to murder a South Carolina farmer. Police and FBI agents arrested a wealthy businessman and later learned that, even behind bars, he had the power to corrupt and kill.

Six black males had been brutally murdered--two had their hearts cut out. The only thing connecting the victims was their ethnicity and the fact that each had been shot with .22 caliber bullets.

New Jersey millionaire Frank Black flew to Florida to close a major business deal and never came home. FBI Agents learned of a mystery woman in Florida who was meet Black. Eventually they untangled a web of deceit that led to a vengeance killing.

A television producer was gunned down in his New York office. Four years later and a continent away, a man told Los Angeles police he had been hired to murder two exotic dancers. Investigators linked the two crimes and uncovered a businessman willing to kill to protect his interests.

Domestic terrorism is an especially vivid threat to Americans; the FBI has created specialized teams to root out and dismantle terrorist operations, and put away those criminals whose secretive, leaderless cells are well armed and very dangerous.

After a string of bank robberies in Illinois, Chicago, the FBI began to suspect that a police officer was responsible for the crimes. With the holdups becoming increasingly violent, authorities set out to capture the dangerous killer.

FBI agents began investigating New York gas station mogul Gurmeet Dhinsa for gas pump rigging. They learned that he enforced his mob-like operation with brutal violence.

In 1993, a 74-year-old man is found suffocated in his home with his credit cards stolen. Investigators were alerted that the killers had used the man’s credit cards and with this information, the FBI was able to link the crime to an escaped prisoner.

The 1987 murder of Boston Police Department officer Roy Joseph Sergei and the resulting joint FBI – BPD – Mexican Federal Police search for professional bank robber Ted Otsuki.

This special episode examines previous cases to learn about the investigative techniques and innovations used by the FBI.

In 1976, a car bombing in Washington DC’s Embassy Row claimed the lives of a former Chilean ambassador and his assistant. During the investigation, it became apparent to FBI agents that a foreign government had ordered the attack.

In 2000, the FBI was overwhelmed with investigations in Seattle, which had the third-highest number of bank robberies in the nation. Agents focused on a series of heists in which two armed men seemed to know where the banks stored their money.

In December 1981, a New Jersey State Trooper was shot to death on the side of Interstate 80. Fingerprints on the suspect’s vehicle pointed to a fugitive wanted on bank robbery charges.

The FBI began a massive undercover operation designed to expose the Chicago Mafia's infiltration into the city's surrounding suburbs.

In 1996, a series of bank robberies in Texas and California were linked by FBI who then established a modus operandi. A year later, the robbers took hostages during a heist in Las Vegas and the FBI was tasked with ending their spree.

In the 1980s, the FBI investigated wide-scale corruption among the detectives of the San Juan, Puerto Rico Police Department. One detective broke the blue wall of silence and went undercover to help the FBI end the corrupt cops' activities.

A wealthy young mother was abducted in front of her in-laws’ home. To find the woman and her abductor, investigators would have to first determine the motive.

A mother discovered her 10 year-old son was missing from his school. The search would cover a thousand miles. Agents were raced to find the kidnapper and the missing child.

In a Georgetown coffee shop, three employees were shot to death. Metro D.C. police turned to the FBI for help, hoping the Bureau’s technical expertise could bring justice for the victims of the triple homicide.

5-year-old Melissa Brannen disappeared from a Christmas party on Dec. 3, 1989, leaving behind a family wracked with anguish.

A Nebraska sheriff's deputy sees a man wanted for firearms violations and tries to arrest him. But the man begins shooting, leading to a high-speed pursuit and wounded cops. The FBI helps track the man across state lines

Young women were being abducted from their own front yards in broad daylight. The FBI was determined to put an end to the serial killer's deadly game of cat and mouse.

Two brothers abduct a banker. FBI agents slowly pieced together tiny shreds of evidence.