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.

The body of 23 year old Robin Bishop was discovered near her car on a remote highway. After acquitted in two state trials, Gwaltney was convicted of the murder in the federal trial. The FBI was able to convince the third jury.

Thomas Dillon killed five outdoorsmen over a period of three years in rural Ohio. A mother's letter published in the newspaper addressing the murderer of her son prompted the killer to respond. Thomas Dillon was arrested and ultimately convicted.

A young mother and her two daughters were sexually assaulted and brutally murdered in Anchorage, Alaska. With only one piece of forensic evidence, a wash rag carrying pubic lice with which the killer used to clean himself, the FBI helped convicted the woman's nephew, Kirby Anthoney on all three counts of murders.

Two couples found themselves on the same deserted island paradise, but only one couple left alive. Buck Walker and Stephanie Sterns arrived in Hawaii on the Sea Wind, which belonged to the missing couple, Mac and Muff Graham. Years later, Buck Walker was convicted of murder.

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.

No suspect had emerged after the rapes and murders of ten women near Tampa, Florida in 1984. When one of the killer's victims survived, the FBI was able to identify 31-year-old Bobby Joe Long as the suspect. Long was later convicted on eight of the murders and rape.

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

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.

Claude Dallas lived the life of a cowboy -- a loner and distrustful of authority. When two game wardens confronted Dallas about his deeds, they were shot and killed. After a massive manhunt , Dallas was captured and convicted, but he escaped prison within months.

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.

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.

On June 21, 1964, three civil rights workers, who set out to educate southern blacks about receiving the right to vote, disappeared in Mississippi. The FBI gained the trust of an informant, whose information led to the conviction of seven local Ku Klux Klan members.

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.

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.

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.

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

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.

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

A Judge and his politician wife were brutally murdered in their home. The FBI uncovered a corrupt local government and a group of violent criminal conspirators.

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.

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

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

A young mother and her infant son mysteriously disappeared from their home. A new DNA technique ended the mystery.

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

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.

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 sniper murdered two young black men as they jogged with two white women. The FBI placed their suspect on their Ten Most Wanted list and began an intense manhunt.

Two brothers gained national attention after a videotaped shoot-out with state and local officers in Wilmington, Ohio. The brothers escaped and fled the state.

Two officers had been shot and one had been murdered in Washington, D.C.. Each had been sitting in their patrol cars when a man sneaked up and opened fire. The FBI was brought in to help catch the cop killer, and this led to a violent gun battle.

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.

A 14-year-old girl ran away from her mother's home and disappeared without a trace. A farmer later discovered the young girl's remains in an Illinois barn.

A woman vanishes, and police suspect that her powerful ex-lover, a married man, was responsible. When investigators can't find the woman's body or the murder weapon, the FBI's only hope was to go undercover and turn brother against brother.

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.

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

A serial killer dupes FBI agents while eluding a nationwide manhunt.

A stranger snatched an eight-year-old girl as she played in her Tucson, Arizona neighborhood. Within hours, a drifter who was out on parole for abducting and molesting children, but he was nowhere to be found and time had run out.

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.

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.

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.

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.

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

Police and FBI agents track a serial killer in a cross-country manhunt.

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.

A armored car robbery near New York City left one guard dead and another critically wounded. The FBI suspected a large group of domestic terrorists with a history of violent crime.

A California man was found dismembered. The murder suspect was found six months later when he was caught robbing an Arizona bank and sentenced to life. When he escaped from prison, the FBI led a manhunt for the killer.

David Wilkey was shot to death on a hunting ground in rural Virginia. When this seemed to be an accident, investigators suspected foul play. Two years later, a man contacted North Carolina FBI agents with a complex story of conspiracy and murder-for-hire.

On a summer night in 1990, the body of a suspected drug courier was discovered burning in a Minnesota alley. The FBI worked with local police to uncover a crime ring run by a drug lord who used violence and intimidation to keep those around him silent.

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.

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.

Bank robbers raided cities across seven states. The stakes were raised when the FBI discovered the robbers had an agenda beyond their personal wealth. The FBI needed to capture the leaders before their organization grew.

A cross-country crime spree terrorized the nation. A trail of stolen vehicles and murder victims across seven states led agents on a hunt for two suspected killers. The killers were always one step ahead of the FBI agents.

A class field trip ended with an 11-year-old girl missing. The FBI joined the investigation in an urgent search for the missing girl.

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.

A radio dispatcher notifies agents of a missing armored van and guards.

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.

A young mother was gunned down in front of her children. Family members offered a startling clue of the secrets of the woman. Investigations revealed a web of money, drugs and murder.

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.

Two young men went on a crime spree of robbery, kidnapping and murder, and then disappeared. The pursuit would take FBI agents across six states.

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.

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.

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.

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.

A gunman fired into rush hour traffic. The brazen daytime shooting of employees from the Central Intelligence Agency stunned the country.

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.

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.

A 13-year-old was kidnapped on her way to school. The father drove hundreds of miles through the night to deliver the ransom cash to rescue his young daughter.

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

Chronicling an investigation that took authorities across Alabama to Virginia in search of cousins suspected in seven deaths, robbery and possession of multiple firearms.

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

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.

On June 19, 1985, convicted bank robber Terry Conner and his partner-in-crime, Joseph Dougherty, escaped on their way to Dougherty's trial. In September, the fugitives used Conner's old m.o. to make the biggest bank robbery in Wisconsin history.

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

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.

The son of a successful real estate developer was kidnapped. After the father received a $3 million ransom demand, the FBI became involved. Criminal profiling helped track down the kidnapper.

Three Black men take Amy Shaw's family hostage at her parents SC home. Jeburk forces Amy to return to the bank were she worked in GA and break into the vault.

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

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.

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.

The 1992 kidnapping and murder of Martha Doe Roberts.

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.

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.

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 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.

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 Richmond, VA, two bank robbers escaped after opening fire on officers responding to the call. When the FBI arrived, agents found one bank teller dead, another wounded; the bank’s security guard had been shot four times, yet was still alive.

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.

An innocent Milwaukee teen was kidnapped by four gunmen who demanded $30,000 from his family to guarantee his safe return. The victim’s family contacted police and the FBI was brought in to help retrieve the boy,

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.

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 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.

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.

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 1987, Cuban prisoners at the Atlanta Federal Prison used homemade weapons to overthrow the staff. Soon, the inmates controlled most of the buildings, taking over 100 hostages. The FBI was forced to negotiate with the hostiles to end the standoff.

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.

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 a suburb of Las Vegas, two robbers ambushed an armored car, killing both guards and seizing thousands of dollars. Authorities linked the crime to a series of armed robberies on gambling houses, including the MGM Grand Hotel and Casino.

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.

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

In the 1970s, a Croatian terrorist group linked to the National Resistance party committed acts against non-supportive Croatians living in the US. With the help of an informant, the FBI convicted members of crimes ranging from conspiracy to murder.

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 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.

An escapee from Castro's Cuba was the mastermind behind terrorist organization Omega 7. This group sought to carry out their mission through bombings and assassinations, financing their crimes through extortion and by aiding drug traffickers.

In the 1970s and 80s, a Puerto Rican separatist group, FALN, set off bombs in major U.S. cities. Advocating complete independence for Puerto Rico, the group went on a major bombing spree and FBI agents found themselves racing against time to put a stop to their violent activities.

In 1990s Philadelphia, a ruthless grab for power led to a full-scale mob war. Using informants and high-tech surveillance, the FBI infiltrated the most powerful mob family in the city and sought to bring it down before innocents were killed.

In the 1980s, the FBI targeted a sharp bank robber known as the Shootist. He had performed more than 50 robberies across California, Texas and Washington with military precision, claiming the longest string of unsolved bank robberies in history.

The Los Macheteros terrorist organization sought to end U.S. rule of Puerto Rico through extreme violence. When the group claimed they attacked 18 unarmed servicemen traveling near San Juan, the FBI was called to investigate the ruthless killers.

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.

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 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 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.

After a parole officer was found shot dead in his car, the FBI, DEA and NYPD struggled to contain gang-related drug violence. Authorities sought to put two drug kingpins, Howard “Pappy” Mason and Lorezno “Fat Cat” Nichols, behind bars for the crime.

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.

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.

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.

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.

Dartmouth Professors Susanne and Half Zantop are found brutally murdered in their New Hampshire home. With no trace of forced entry, the FBI Behavioral Science Unit found two teenagers were responsible for the heinous crime.

A series of bizarre shootings terrorized the small town of East Point, GA, and left two people dead and two others critically wounded. As the body count climbed, the killer taunted law enforcement with mysterious notes.

In Boston, FBI agents tracked down a gang of robbers who specialized in armored car takedowns. As the robberies grew increasingly more violent, authorities launched a complex sting to trap the deadly ring of thieves.

In the 1990s, a gang based in the U.S. Virgin Islands smuggled large amounts of cocaine into mainland America. In an investigation spanning from Georgia to South America, the FBI and DEA were able to identify the leader and bring down the drug ring.