Some mysteries last because the evidence has run out. Others last because there is plenty of it and none of it adds up to an answer. The three cases here, a 1971 airplane hijacking, a vanished 16th-century colony, and a serial killer who taunted the press with codes, are among the best-known unsolved cases in American history. Each has been picked over by professionals and amateurs for decades.
This article sticks to what is documented. For each case I separate what investigators know, what they have only theorized, and what has been ruled out. Near the end, a case file table puts all three side by side.
Case One: D.B. Cooper (1971)
What happened
On the day before Thanksgiving in 1971, a man bought a one-way ticket on Northwest Orient Airlines Flight 305, a short hop from Portland to Seattle on a Boeing 727. He gave his name as Dan Cooper. Soon after takeoff he handed a flight attendant a note saying he had a bomb. He showed her what appeared to be wires and batteries in his briefcase.
His demands were specific: $200,000 in $20 bills, and four parachutes. The plane circled until the FBI and the airline assembled the money and equipment, then landed at Seattle-Tacoma. Cooper released the passengers and some of the crew, took the cash and parachutes, and told the remaining crew to fly toward Mexico City at low speed and low altitude with the rear stairs lowered.
Sometime after 8 p.m., somewhere over the dark, rainy forests of southwest Washington, he jumped. The plane landed in Reno, Nevada, and agents searched it. The man was gone.
The famous name is a mistake. According to the FBI’s own history of the case, a reporter’s confusion with an unrelated suspect named D.B. Cooper produced the label that stuck, and the real alias was “Dan Cooper.” The FBI’s official case history explains how the investigation unfolded.
What investigators actually found
The physical evidence is real but thin:
- A clip-on tie and tie clip left on the plane. Later analysis of the tie found unusual particles, including rare metals, that sparked speculation about his job. No suspect has been tied to that work conclusively.
- Cigarette butts left in the seat area, which in later years were considered for DNA testing. A usable profile that would identify a person has never been publicly confirmed.
- Two unused parachutes. Cooper took the two he used and left the others.
- Money. In 1980, eight-year-old Brian Ingram found about $5,800 in decaying $20 bills while on a family outing on the Columbia River bank. The serial numbers matched the ransom. That is the only confirmed recovery of the cash. None of the rest has surfaced in circulation.
The money find is more puzzling than helpful. It shows the cash reached the river somehow, but experts have argued for decades about whether it washed down from higher ground or was buried and exposed over time. Either way, it is consistent with Cooper dying on the jump, though it doesn’t prove it.
The suspects
By the time the FBI formally scaled back its active investigation in 2016, after 45 years, it had examined well over 800 suspects. Several names recur in the literature:
- Richard McCoy Jr. hijacked a plane using a very similar method in 1972 and was later killed in a shootout with law enforcement. Investigators looked at him carefully, but he doesn’t fit witnesses’ descriptions in some respects, and he was reportedly at home at the time.
- Kenneth Christiansen, a former paratrooper and airline employee, has been proposed by independent researchers.
- Duane Weber is the subject of a widely repeated story that he confessed to his wife on his deathbed. That claim hasn’t been supported by physical evidence.
- Robert Rackstraw, a former Army pilot, was investigated and cleared in the 1970s, and his name continues to resurface in books and documentaries.
None of these identifications has survived scrutiny to the standard the FBI would need.
The status
In July 2016 the FBI announced it was suspending active work on the case. It stated that it would still accept physical evidence, especially any of the ransom bills. The prevailing view among many investigators is that a man jumping into a freezing, rainy night over wilderness, with limited gear and no clear landing zone, probably did not survive. But “probably” is not “proven,” and no body has ever been found.
Case Two: The Lost Colony of Roanoke (1587)
What happened
This is the oldest of the three, and in some ways the strangest.
England’s earliest attempts to settle North America were on Roanoke Island, in what is now North Carolina. A first expedition under Ralph Lane in 1585 left within a year. Then, in 1587, a group of about 115 men, women, and children sailed under the governor John White. Among them were White’s own daughter and her husband. In August, his daughter gave birth to a girl, Virginia Dare, the first English child born in the Americas.
Soon after, White returned to England to get more supplies. He expected to be back within months. Instead, the Anglo-Spanish War, including the threat of the Spanish Armada, kept English ships tied up at home. White did not make it back to Roanoke until August 1590, three years later.
He found the settlement deserted. There were no signs of a battle. The houses had been taken down, and the word CROATOAN was carved into a post. The letters “CRO” were found on a tree. Before leaving, White had arranged with the colonists that if they had to move because of danger, they would carve a Maltese cross. There was no cross. A storm prevented White from searching Croatoan Island, the area now known as Hatteras, and he sailed home. He never found his family.
What archaeologists have found
For centuries this was just a story. Over the last few decades, researchers have turned it into a search with real fieldwork. The National Park Service manages Fort Raleigh National Historic Site on Roanoke Island, and the First Colony Foundation has funded and published much of the recent archaeology.
The most notable developments:
- A hidden symbol on John White’s map. In 2012, researchers examining a watercolor map held by the British Museum noticed a patch covering part of the drawing. Under it was what appeared to be a fort symbol near the Albemarle Sound, inland from Roanoke Island. This reinforced the idea that colonists may have planned to move there. Digging in that area, often called “Site X” in Bertie County, has turned up 16th-century English-made items, including ceramics. These are consistent with an English presence, but they are not a smoking gun, because they could also be from trade or from later arrivals.
- Evidence on Hatteras Island. Excavations at Cape Creek, on the island the colonists called Croatoan, have turned up artifacts from the late 1500s that include English items alongside Native American materials. That fits with the idea that at least some colonists joined local communities.
- No mass grave and no massacre site. Despite the searching, no evidence of a large-scale killing has been found.
The theories
- Assimilation. The leading hypothesis is that the colonists split up and moved in with friendly Native groups, including the Croatoan people, whose name was carved on the post. It matches the one message they left.
- Relocation inland. The White map patch supports the idea of a move up the Albemarle Sound or toward the Chesapeake Bay.
- Violence or disease. Early Jamestown colonists later heard reports about English survivors being killed. These accounts are secondhand and disputed.
- Lost at sea. Some suggest the colonists tried to sail home or to a better site and were lost.
Scholars who have studied the evidence, including researchers affiliated with the First Colony Foundation, generally favor the dispersal theory: the colonists scattered among several communities rather than meeting a single dramatic end. The documents don’t allow certainty.
The status
Unresolved. There is no confirmed identification of a surviving colonist or descendant. Archaeology continues, and any further finds would most likely come from careful excavation rather than from a single dramatic discovery.
Case Three: The Zodiac Killer (1968 to 1969 and After)
What happened
Between December 1968 and October 1969, a killer or killers attacked couples and a taxi driver in Northern California. Authorities confirm five murders and two attacks in which the victims survived:
- December 1968: David Faraday and Betty Lou Jensen were shot on Lake Herman Road in Benicia.
- July 1969: Darlene Ferrin was killed and Michael Mageau wounded at Blue Rock Springs in Vallejo.
- September 1969: Bryan Hartnell and Cecelia Shepard were stabbed at Lake Berryessa. Shepard died of her wounds.
- October 1969: Paul Stine, a cab driver, was shot in San Francisco.
The killer’s most notable move was communication. Beginning in the summer of 1969, he mailed letters to Bay Area newspapers, some containing ciphers, and demanded they be published. He called himself the Zodiac. He claimed more victims than police have ever confirmed, and some of these claims are generally treated with skepticism.
What investigators actually found
The ciphers. The first of the 1969 cryptograms, known as Z408, was cracked within days by a married couple, Donald and Bettye Harden, a teacher and his wife from Salinas. Its decoded message was a rambling statement about enjoying killing and did not give the writer’s name.
A second cipher, the 340-character message mailed in November 1969, resisted solution for more than 50 years. In December 2020, a team of three independent codebreakers, David Oranchak, Sam Blake, and Jarl Van Eycke, announced a solution, which the FBI confirmed. The text was again a taunt and did not reveal an identity. It is a remarkable achievement, but it didn’t answer the question everyone cared about.
Other cipher fragments attributed to the killer remain unsolved. Oranchak publishes his research on his site, which is worth reading if you want the codebreaking method in detail.
The physical evidence. Investigators have bullet casings, fingerprints from the cab, a bloody shirt piece mailed to a newspaper, and saliva on letter stamps and envelopes. DNA analysis has been attempted. In 2002, a partial profile obtained from the back of envelope stamps did not match Arthur Leigh Allen, the best-known suspect. Skeptics point out that stamps and envelopes can be handled by many people, so such a profile is not necessarily the killer’s.
The suspect. Allen, who died in 1992, was investigated heavily by detectives who believed in his guilt. He was never charged. Fingerprint, handwriting, and DNA comparisons did not produce a match.
Controversial claims
In 2021, a private group called the Case Breakers publicly named another man, Gary Francis Poste, as the Zodiac. The San Francisco Police Department and the FBI did not endorse that finding, and independent experts challenged it. It’s worth noting how often confident announcements like this appear in cases like Zodiac, and how rarely they have held up under official review.
The status
Law enforcement agencies in California have treated the case as open, though activity has varied over the years. Please verify the current status directly with the relevant police departments before publishing this article, since agencies sometimes change case classifications.
The Case File Table
| D.B. Cooper | Roanoke Colony | Zodiac Killer | |
|---|---|---|---|
| Date | Nov. 24, 1971 | 1587 (found abandoned 1590) | 1968 to 1969 (letters later) |
| Location | Flight from Portland to Seattle; jump over southwest Washington | Roanoke Island, North Carolina | San Francisco Bay Area |
| Key evidence | Tie and clip, cigarette butts, $5,800 of ransom found in 1980 | Word “CROATOAN” carved, hidden fort symbol on White’s map, English artifacts at Site X and Hatteras | Ciphers, letters, bullet casings, partial DNA, fingerprints |
| Main theories | Died in the jump; survived and vanished | Assimilation with Native communities; inland relocation; violence | Several suspects, none proven |
| Strongest piece of evidence | Ransom bills found on the river bank | English-made artifacts at Site X and Hatteras | Z340 cipher solved, confirming the writer’s style but not identity |
| Biggest gap | No body, no identification | No survivors or graves found | No definitive DNA or fingerprint match |
| Official status | FBI suspended active investigation in 2016; accepts new evidence | Open historical and archaeological question | Open (verify current status) |
What These Cases Have in Common
A few patterns run through all three.
First, the physical evidence is smaller than the legend. Cooper left a tie and some cigarette butts. Roanoke left one carved word. The Zodiac left letters and a handful of forensic traces. In each case, decades of public interest have built a much bigger story on a small base.
Second, the best breakthroughs are quiet ones. The solved Zodiac cipher, the hidden symbol on a 400-year-old map, and the ransom bills found by a child all came from patient work and luck, rather than from the dramatic confessions and “final answers” that periodically make headlines.
Third, confident claims deserve caution. Each of these cases has attracted people announcing that they have finally solved it. Almost none of those announcements has held up. The honest answer in each case is that the evidence supports some theories more than others, but no theory is proven.
Why We Keep Looking
Part of the pull is simply human. These cases involve ordinary people in extraordinary circumstances: a flight crew handed a note, a mother and her infant daughter on a remote island, a teenage couple parked on a quiet road. Behind the mystery are real people and real families, which is worth remembering whenever a case becomes entertainment.
And the work isn’t finished. Archaeologists are still digging in North Carolina. Codebreakers are still working on the remaining Zodiac ciphers. Anyone who finds a $20 bill from 1969 with the right serial number should still call the FBI.
Frequently Asked Questions
Is D.B. Cooper’s case still open?
The FBI stopped actively investigating in 2016 but said it would continue to accept physical evidence, especially any of the ransom money.
What does “CROATOAN” mean?
It refers to Croatoan, the name of an island and a Native American community in the area. Historians believe it was the colonists’ note about where they had gone.
Has the Zodiac Killer been identified?
No identification has been accepted by law enforcement. The 340-character cipher was solved in 2020, but its message did not name him.
Did anyone survive the Zodiac attacks?
Yes. Michael Mageau and Bryan Hartnell survived their attacks and gave descriptions to investigators.
Where can I read more?
Start with the primary sources below, then the books by researchers who have worked on each case.
Sources and Further Reading
- FBI: D.B. Cooper Hijacking
- National Park Service: Fort Raleigh National Historic Site
- First Colony Foundation
- Zodiac Ciphers (David Oranchak)
- Wikipedia: D. B. Cooper, Roanoke Colony, and Zodiac Killer, useful for tracking down the original sources they cite
