FBI Issues Mobile App Warning, Plus 32 Most Significant FBI Cases in American History

By Lori Kinney Updated Published
This post may contain links from our sponsors and affiliates, and Flywheel Publishing may receive compensation for actions taken through them.
FBI Issues Mobile App Warning, Plus 32 Most Significant FBI Cases in American History

© TrialsB W524 1875 tall, rear c... (CC BY 2.0) by Yale Law Library

A handful of mobile apps have been linked to foreign adversaries, including Russia and China. The FBI has stepped in to warn users not to download these apps, as they could pose a threat to personal information. In what sounds like a dystopian novel, the risks include data harvesting and surveillance. The apps in question share an assortment of qualities, like excessive permissions and accessing files or contacts without justification. These growing cybersecurity concerns come in the midst of a tense geopolitical climate. The FBI further reminds mobile users to stay vigilant and only download apps from trusted developers.

Prior to the early 1900s, the United States had no national investigative agency until the establishment of the Federal Bureau of Investigation (FBI). Since its inception, the FBI has been involved in some of the most significant criminal cases in American history.

24/7 compiled a list of the most significant cases in U.S. law-enforcement history, using information sourced from the FBI’s website. Our selection process involved editorial judgment, focusing on each case’s importance, challenges, historical relevance, and national significance.

According to information from the FBI’s website, some of their most consequential cases have included kidnappings, interstate robberies, aircraft hijackings, bombings, murder, and the killing of law enforcement officers. Established in 1908 by Attorney General Charles Bonaparte as a special agent force within the Department of Justice, the FBI was created in response to new national laws like the Espionage Act. Under the leadership of J. Edgar Hoover, who took charge in 1924, the FBI became an important entity in law enforcement.

Throughout the decades, the FBI has handled high-profile cases that received national attention, investigating organized crime, civil rights violations, terrorism, cybercrime, and other significant matters. (Check out 22 notorious unsolved crimes in American history.)

This post was updated on July 30, 2025 to include the FBI’s recent app warning.

Here are 32 investigations that redefined U.S. law enforcement: 

Rosenberg Espionage

National Archives and Records Administration, Public domain, via Wikimedia Commons
  • Outcome: The Rosenbergs were executed in 1953

In the early years of the Cold War, the FBI arrested multiple members of a spy ring, including Julius Rosenberg and his wife Ethel. They were accused of giving atomic secrets to the Soviet Union, convicted of espionage, and in 1953, during the cold war, they became the first and only Americans executed for espionage.

Alcatraz escape

mysiann / Flickr
  • Outcome: Unsolved

During a routine early morning bed check at Alcatraz prison on June 12, 1962, authorities discovered that three convicts were not in their cells: John Anglin, his brother Clarence, and Frank Morris. In their places were dummy heads made of plaster, flesh-tone paint, and actual human hair. The prison went into lockdown, and an intensive search began. It is not known if the escapees drowned or had made the only successful escape from The Rock.

Black Dahlia murder

Elizabeth Short
Los Angeles Police Department/Wikimedia Commons

  • Outcome: Unsolved

On the morning of Jan. 15, 1947, a mother and her child in a Los Angeles neighborhood came across a horrific scene of the body of a young woman’s severed in half. Despite the mutilation, there was no blood, suggesting she was murdered elsewhere and then moved to that location. The victim was Elizabeth Short, a 22-year-old aspiring actress. She became known as the “Black Dahlia” by the media because of her preference for wearing sheer black clothing and the film “The Blue Dahlia.” The case remains unsolved.

Brinks robbery

chicagocrimescenes / Flickr
  • Outcome: 8 people found guilty for armed robbery

On the evening of Jan. 17, 1950, employees of the security firm Brinks, Inc., in Boston, were returning sacks of undelivered cash, checks , and other items to the company safe. Just before 7:30 p.m., five men entered the building, bound the employees, and grabbed the loot. They swiped more than $1.2 million in cash and another $1.5 million in checks and other securities , the largest robbery in the U.S. at the time. Eight men were eventually found guilty of the robbery.

Charles Ross kidnapping

  • Outcome: Suspect confessed to kidnapping and murder and executed

On the morning of Sept. 25, 1937, Charles S. Ross, the wealthy president of a greeting-card company, was driving toward Chicago on when he was pulled over and kidnapped at gunpoint by two men. Ross and one of the kidnappers, James Atwood, were later killed by John Henry Seadlund, who was eventually arrested and executed.

D.B. Cooper hijacking

Public Domain / Wikimedia Commons
  • Outcome: Unsolved

A man who identified himself as D.B. Cooper hijacked Northwest Orient Flight 305 out of Portland, Oregon, on Nov. 24, 1971. He demanded and received $200,000 in ransom money upon landing in Seattle. The plane took off for Mexico City , and during the flight he parachuted into the woods in the American West and was never seen again.

Murder of Special Agent Edwin C. Shanahan

Courtesy of the FBI
  • Outcome: Man served 28 years of a 35-year jail term

Special Agent Edwin C. Shanahan wanted to apprehend Martin James Durkin, a professional automobile thief, for violatiing the National Motor Vehicle Theft Act. On Oct. 11, 1925, while attempting to arrest Durkin in Chicago, Shanahan became the first FBI agent killed in the line of duty. At that time, killing a special agent was not a federal offense. That law was enacted in 1934. Durkin served 28 years of a 35-year sentence and was released in 1954. He passed away in 1981.

Frank Sinatra, Jr., kidnapping

Public Domain / Wikimedia Commons
  • Outcome: Kidnappers caught and convicted

Frank Sinatra, Jr., son of iconic singer Frank Sinatra, was kidnapped on Dec. 8, 1963, at a lodge in Lake Tahoe, Nevada, by two 23-year-old men from Los Angeles and held for $200,000 ransom. Young Sinatra, who was trying to start his own singing career, was found unharmed and the money was recovered. Three kidnappers were convicted.

Reservation murders

Public Domain / Wikimedia Commons
  • Outcome: Suspect sentenced to two consecutive life terms

FBI Agents Jack Coler and Ronald Williams were murdered by Leonard Peltieron June 26, 1975, at Pine Ridge Indian Reservation  in the southwestern corner of South Dakota. At the time of the shootings, Peltier had an outstanding warrant for his arrest. He was subsequently sentenced to serve two consecutive life terms.

Bombing of United flight

Public Domain / Wikimedia Commons
  • Outcome: Jack Gilbert Graham found guilty of murder and executed

On Nov. 1, 1955, United Air Lines Flight 629 with 44 people aboard took off from Stapleton Airport in Denver bound for Portland, Oregon, but an explosion on the plane caused it to crash on a beet farm near Denver. The downed aircraft was the work of Jack Gilbert Graham, who stood to inherit insurance money upon the death of his mother who was on that plane.

Army deserters kill FBI agent

Courtesy of the FBI
  • Outcome: Suspects sentenced to life imprisonment

On March 13, 1942 Army deserters James Edward Testerman and Charles J. Lovett shot and killed special agent Hubert J. Treacy, Jr. in a restaurant in Abingdon, Virginia. Following a gun battle,hey were apprehended  and sentenced to life in prison.

Greenlease kidnapping

Courtesy of FBI
  • Outcome: Kidnappers executed

Bobby Greenlease Jr., 6-year-old son of a wealthy car dealer, was kidnapped from school in Kansas City, Missouri, on Sept. 28, 1953, held for $600,000 ransom and then murdered. Suspects Carl Hall and Bonnie Heady were arrested and a jury in the federal court in Kansas City, recommended the death penalty after only an hour and eight minutes of deliberations. They were executed in the gas chamber on Dec. 18, 1953.

JFK assassination

Wikimedia Commons / Public Domain

  • Outcome: Oswald gunned down by Jack Ruby

President John F. Kennedy was assassinated in Dallas on Nov. 22, 1963. The FBI conducted approximately 25,000 interviews and pursued tens of thousands of investigative leads, ultimately concluding that assassin Lee Harvey Oswald acted alone in the president’s killing.

Weyerhaeuser kidnapping

Public Domain / Wikimedia Commons
  • Outcome: Three suspects sentenced

On May 24, 1935, George Weyerhaeuser, the 9-year old son of lumber tycoon J.P. Weyerhaeuser of Tacoma, Washington, disappeared on his way home from school and was held for ransom initially put at $200,000. FBI agents apprehended three kidnappers and retrieved more than $157,000 of the ransom money.

Special Agent J. Brady Murphy slain

Courtesy of the FBI
  • Outcome: John Elgin Johnson killed in shootout with FBI agents

In a scene reminiscent of a movie, Special Agent J. Brady Murphy was fatally wounded during a gun battle with murder suspect and career criminal John Elgin Johnson in a Baltimore movie theater on Sept. 25, 1953.

Jonestown mass suicide

  • Outcome: Cultist Larry Layton sentenced to life in prison

An investigation into abuse at Jim Jones’ Peoples Temple the jungle of Guyana on Nov. 14, 1978, led to the death of California Congressman Leo Ryan and then the poisoning of more than 900 cultists, including more than 200 children.

Krupp diamond theft

Courtesy of the FBI
  • Outcome: Suspects arrested and convicted

The theft of a valuable diamond ring and $700,000 on April 10, 1959, by three men at the Krupp family ranch in Nevada triggered a nationwide FBI chase.  The chase ended with the arrest of one man in a hotel room in Elizabeth, New Jersey. The ring’s diamonds were reassembled, and the precious band was later purchased at auction by Richard Burton for his then-wife Elizabeth Taylor.

Special Agent William R. Ramsey murder

Courtesy of the FBI
  • Outcome: Suspect killed, two others arrested

On May 3, 1938, Special Agent William R. Ramsey died from wounds that he sustained while attempting to arrest one of the suspects, Joe Earlywine, in an Indiana bank burglary that had taken place the previous year. Ramsey was able to shoot and kill Earlywine before he died. Two other paroled convicts were arrested.

Judge Vance murder

Joe Raedle / Getty Images
  • Outcome: Walter Moody executed in 2018

In late 1989, the nation was rocked by a series of bombings in the Southern United States aimed at federal buildings, law enforcement officials, and the Jacksonville office of the NAACP. Judge Robert Vance was killed in his suburban Alabama home on December 16, and two days later, Robert Robertson was murdered in Atlanta. The investigation led to Walter Leroy Moody, who held a grudge against Judge Vance from a previous case. Moody was executed in 2018.

Lindbergh kidnapping

Keystone / Hulton Archive via Getty Images
  • Outcome: Bruno Richard Hauptmann executed

Charles Augustus Lindbergh, Jr., 20-month-old son of the famous aviator and author Anne Morrow Lindbergh, was kidnapped on March 1, 1932, from the nursery on the second floor of the Lindbergh home near Hopewell, New Jersey. The child died during the ordeal and the kidnapper, Bruno Richard Hauptmann, was executed in the electric chair.

Robbery spree on East Coast

Public Domain / Wikimedia Commons
  • Outcome: Suspects sentenced to life in prison

After forming an alliance in an Ohio prison, Albert Nussbaum and Bobby Wilcoxson robbed eight banks, accumulated an arsenal of weapons, murdered a bank guard, and detonated several bombs in the nation’s capital in 1961. Their partnership soured, leading to their capture in the countryside outside of Buffalo. Both were sentenced to life in prison.

Osage murders case

Public Domain / Wikimedia Commons
  • Outcome: Cattleman WIlliam Hale and his henchmen sentenced to prison

A series of murders committed against members of the Osage Nation in Oklahoma, who owned rights to recently discovered oil and earned royalties from its sale, was solved when the FBI apprehended business mogul William Hale and his henchmen. The story is the subject of the Martin Scorsese-directed film “The Killers of the Flower Moon.”

Patty Hearst abduction

Public Domain / Wikimedia Commons
  • Outcome: Hearst found guilty of bank robbery and other charges; President Carter commuted her sentence

On February 4, 1974, Patty Hearst, granddaughter of newspaper magnate William Randolph Hearst,  was abducted from her dorm room at the University of California, Berkeley, by armed anti-capitalist radicals of the Symbionese Liberation Army(SLA) in California. The SLA demanded a $2 million ransom to distribute to the poor. Patty Hearst was reportedly brainwashed by the SLA and later participated in a bank robbery and helped make explosive devices. She was apprehended on Sept. 18, 1975, and faced charges including bank robbery. President Carter commuted her seven-year sentence after she had served two years.

Unabomber attacks

Stephen J. Dubner / Contributor / Getty Images
  • Outcome: Kaczynski pled guilty and died in prison in 2023

Sixteen incendiary devices sent by mail were detonated between 1978 and 1995, one exploding in the bay of an American Airlines plane and another sent to the president of United Airlines. In all, the bombs killed three people. The case was cracked when the the Justice Department OK’d the newspaper publication of a 35,000-word manifesto by the so-called Unabomber. Social worker David Kaczynski alerted the FBI to similarities between what was published and the writing style of his brother Ted. The FBI tracked down Ted Kaczynski to a shack in Montana. Kaczynski pled guilty and died in prison in 2023.

Hijacking of United Flight

Public Domain / Wikimedia Commons
  • Outcome: Man sentenced to 45-year term in 1973

On April 7, 1972, a man brandishing a hand grenade and a pistol hijacked a United Airlines flight bound for Los Angeles from Newark, N.J., with a stopover in Denver, and parachuted from the plane over Utah with $500,000 in ransom money. Vietnam War veteran and helicopter pilot Richard Floyd McCoy, Jr., was eventually tracked down and sentenced to a 45-year jail term for air piracy. In 1974, McCoy escaped from the federal penitentiary in Lewisburg, Pa., with two other convicts and was eventually killed in a shootout with law enforcement.

Murder of Anne Marie Fahey

DenisTangneyJr / iStock via Getty Images
  • Outcome: Convicted in 1999, died in prison in 2011
  • Weinberger kidnapping done
  • Outcome: Suspect executed in 1958

One-month-old Peter Weinberger was abducted from his home in Westbury, N.Y., on July 4, 1956, by Angelo LaMarca, a financially struggling taxi dispatcher and truck driver. LaMarca left a ransom demanding $2,000 but became panicked when police and the press swarmed the money drop-off site. He abandoned the baby, who tragically passed away later. The FBI identified LaMarca by matching his handwriting with his writing from a previous probation file and arrested him. He was convicted of kidnapping and murder, and was executed in 1958.

Joanne Chesimard terror spree

Public Domain / flickr
  • Outcome: Chesimard escaped from prison and lived underground before being located in Cuba in 1984

Joanne Chesimard , a member of the extremist group Black Liberation Army , fled the U.S. and is wanted for domestic terrorism; bank robbery ; unlawful flight to avoid confinement after escaping prison in New Jersey in 1979 ; and the murder of a New Jersey State Trooper. Chesimard was named a Most Wanted Terrorist by the FBI and is the first woman ever to make the bureau’s list of top terrorists. She is thought to be living in Cuba.

Oklahoma City Bombing

usacetulsa / Flickr
  • Outcome: Anti-government militant executed; co-conspirators sentenced to prison terms

The Oklahoma City bombing took place on April 19, 1995 , when a truck filled with explosives was detonated outside the Alfred P. Murrah Federal Building in Oklahoma City. The explosion killed 168 people and injured hundreds more. Anti-government conspirators Timothy McVeigh , Terry Nichols , and Michael Fortier were found guilty of carrying out the deadliest domestic terrorist attack in U.S. history. McVeigh was executed , Nichols received a life sentence , and Fortier was sentenced to 12 years in prison before being released in 2007.

Murder of Medgar Evers

tonythemisfit / Flickr
  • Outcome: Byron De La Beckwith convicted

Civil rights leader Medgar Evers was gunned down in front of his Mississippi home on June 12 , 1963. Two all-white juries rejected testimony from FBI agents and witnesses to convict Ku Klux Klan member Byron De La Beckwith. The persistence of Evers’ widow Myrlie Evers-Williams forced the FBI to reopen the case. New witnesses were located and De La Beckwith was convicted in 1994. He died in jail in 2001.

German saboteurs

Public Domain / Wikimedia Commons
  • Outcome: All were captured

In July 1941 , prior to America’s entry into World War II , FBI agents arrested German spy Frederick Joubert “Fritz” Duquesne and 32 other German agents after a two-year investigation. The following year , the agency thwarted two teams of German saboteurs who had landed on Long Island and Ponte Vedra Beach in Florida.

Robbers in the Midwest

Public Domain / Wikimedia Commons
  • Outcome: Bonnie and Clyde, Dillinger killed

Holdups of banks and other businesses were common in Depression-era America in the 1930s , and the crimes of robbers Bonnie Parker and Clyde Barrow and John Dillinger commanded the nation’s attention. In 1934 , Bonnie and Clyde were slain in a hail of bullets from law enforcement , and later that year , and Dillinger was killed by special agents outside the Biograph Theater in Chicago while resisting arrest.

Featured Reads

Our top personal finance-related articles today. Your wallet will thank you later.

Continue Reading

Top Gaining Stocks

SMCI Vol: 78,905,633
+$3.22
+10.94%
$32.64
MU Vol: 47,900,620
+$26.12
+7.76%
$362.75
MRNA Vol: 11,890,786
+$2.47
+6.28%
$41.83
GEV Vol: 4,987,865
+$39.32
+6.12%
$681.55
PWR Vol: 2,216,708
+$19.11
+4.27%
$466.75

Top Losing Stocks

CEG Vol: 9,210,686
-$33.49
9.82%
$307.71
VST Vol: 13,329,527
-$13.58
7.54%
$166.60
AMCR Vol: 10,279,220
-$3.22
7.29%
$40.94
WST Vol: 1,505,550
-$19.62
7.02%
$259.79
ALB Vol: 4,817,521
-$10.74
6.18%
$163.04