The Frog Boys Case: The 1991 Daegu Mystery That Remains Unsolved

Introduction

On March 26, 1991, five elementary-school boys from Daegu, South Korea, left their homes and headed toward nearby Waryong Mountain.

They were between nine and thirteen years old.

They were not supposed to be gone for long.

According to a witness account later reported by Korean media, the boys said they were going to collect salamander eggs. But they never returned home.

What followed was one of the largest and most emotionally devastating missing-child searches in South Korean history.

Police officers, soldiers, volunteers and ordinary citizens searched enormous areas for the children. Millions of missing-person flyers were distributed, their photographs appeared on various products and media, and the boys' families spent years searching for them.

For more than 11 years, there was no definitive answer.

Then, on September 26, 2002, human remains, clothing and shoes were discovered on Waryong Mountain.

They belonged to the five missing boys.

The discovery transformed the case from a mysterious disappearance into an even more disturbing question:

How did five children disappear together, die on the mountain, and remain undiscovered for more than a decade?

And most importantly:

Who was responsible for their deaths?

More than three decades after the disappearance, nobody has been convicted for the deaths of the five boys. South Korean authorities have repeatedly revisited the case, and the investigation was reopened in 2019. As of 2026, the case remains unresolved.

Who Were the Frog Boys?

The five boys were students from Seongseo Elementary School in Daegu.

Their names and ages at the time of disappearance were:

The boys lived close to one another and were friends. Their families knew each other, and the children frequently played together.

Later accounts from their families described them as a close-knit group.

The nickname “Frog Boys” became attached to the case because early media reports incorrectly described their destination as a place where they were going to catch frogs or collect frog eggs.

Later reporting clarified that the boys had actually intended to collect salamander eggs.

March 26, 1991 — The Day They Disappeared

March 26, 1991 was not an ordinary school day.

It was a public holiday connected with South Korea's local elections. The country was focused heavily on the historic election, which was the first local election in decades.

The boys were therefore free from school.

During the morning, the five children left their homes in the Daegu area.

According to later accounts, they headed toward Waryong Mountain, a nearby wooded hill that they knew relatively well.

The mountain was not an enormous or remote wilderness. This fact would later become one of the major reasons investigators and the families questioned the idea that the children simply became lost.

A friend reportedly encountered the boys and asked where they were going.

The boys reportedly said they were going to look for salamander eggs.

That was the last known explanation for their destination.

The First Warning Sign

One of the most important early details came from Woo Cheol-won's family.

According to his father, Cheol-won returned home briefly to get a thicker jacket before leaving again.

Later that day, the family learned that he had not shown up for a scheduled taekwondo class.

The realization that Cheol-won was missing eventually led to the discovery that the other four boys were missing as well.

The families began searching.

As the hours passed without the children returning, the situation became increasingly serious.

The Search Begins

Initially, the disappearance did not receive the level of national attention that it would later receive.

The country was preoccupied with the election.

But within days, the case became a national story.

Police began searching Waryong Mountain and surrounding areas.

The search eventually expanded far beyond the mountain.

Police, military personnel, volunteers and civilians participated.

Contemporary and later reports give slightly different totals depending on what is counted, but the scale was enormous. Korean reports commonly cite approximately 320,000 personnel over the course of the search.

More than 140,000 locations were reportedly searched.

Millions of flyers carrying photographs of the children were distributed throughout the country. Later reporting by Korea JoongAng Daily cites approximately 22 million flyers, while older contemporary reporting cites about 8.1 million; the discrepancy appears to reflect different periods or counting methods.

The children's photographs were also reproduced on items including cigarette packs, postcards and videotapes.

The government offered a reward of 42 million won for information leading to the boys.

The Parents' Search

The disappearance destroyed the normal lives of the five families.

The fathers devoted enormous amounts of time to searching for their children.

They traveled across South Korea distributing photographs and asking people whether they had seen the boys.

Some family members eventually left their jobs.

The search continued not only around Waryong Mountain but also at reservoirs, waterways, transportation hubs and other locations.

The families also had to deal with a terrible secondary problem:

false information.

False Tips, Hoaxes and Strange Claims

The case generated hundreds of reports and claims.

Some people genuinely believed they had seen the children.

Others provided information that turned out to be completely false.

According to reports from the period and later accounts, the families received enormous numbers of tips from people claiming to have supernatural knowledge or special information.

Some shamans claimed to know where the children had been buried.

Families followed some of these leads, sometimes traveling considerable distances and searching locations that ultimately contained nothing.

There were also hoax ransom calls.

One caller reportedly claimed to have kidnapped the children and demanded money.

The caller never produced the boys.

Other bizarre explanations eventually circulated, including kidnapping, abduction, secret burial, and even UFO-related theories.

None of those extraordinary claims was established as fact.

The sheer volume of false information made the search even more painful for the families.

A Country Searching for Five Children

The Frog Boys case became much more than a local missing-person investigation.

Their photographs became familiar throughout South Korea.

Television programs discussed the disappearance.

Newspapers repeatedly covered developments.

Ordinary citizens joined searches.

The case became one of the most recognizable unsolved mysteries in modern South Korean history.

Yet despite the enormous effort, no confirmed trace of the children was found for more than a decade.

Theories Before the Bodies Were Found

During the 11-year disappearance, investigators considered numerous possibilities.

They had become lost

One early theory was that the children had gone too far into the mountain, become lost and died from exposure.

This theory became particularly important after their remains were eventually discovered.

However, the families strongly questioned it.

The children knew the area, and the eventual discovery site was not extraordinarily far from their neighborhood.

Kidnapping

Another possibility was that someone had abducted the children.

This theory was strengthened in the public imagination by the ransom calls and various reports claiming the boys had been taken.

However, no credible kidnapping evidence was established.

A stranger or predator

Some people believed the children encountered an adult who harmed them.

This remained possible but was never linked to an identified suspect.

Local youths

Another theory suggested that the children encountered older teenagers or young adults.

This theory became particularly prominent decades later, especially after claims were made about nearby students and a possible tool used in the killings.

But no perpetrator was established.

Other extraordinary theories

Over the years, people also suggested everything from secret abductions to supernatural explanations and UFOs.

These were never supported by reliable evidence.

September 26, 2002 — The Discovery

More than 11 years after the boys disappeared, the case suddenly changed.

On September 26, 2002, a man named Choi Hwan-tae, who was searching for acorns on Waryong Mountain, discovered what appeared to be human bones.

He also found shoes and clothing.

Police were called.

The search of the area revealed the remains of all five missing boys.

The discovery site was on Waryong Mountain, roughly several kilometers from the neighborhood where the boys had lived.

The remains were eventually identified as belonging to the five children using forensic examination, including DNA analysis and dental records.

The mystery of where the boys had gone was finally answered.

But the much darker mystery had just begun.

The First Police Theory: Hypothermia

Immediately after the remains were discovered, police did not initially conclude that the boys had been murdered.

One possibility was that they had become lost and died from exposure to the cold.

The weather on the day of their disappearance was cool and rainy.

Reports cited temperatures ranging from approximately 3.3°C in the morning to 12.3°C around midday.

Police also noted that the remains appeared to have been found together.

This contributed to the initial theory that the boys might have huddled together to preserve body heat.

However, the families were deeply skeptical.

They argued that the children were relatively close to home and familiar with the mountain.

If they were cold or lost, why had all five remained together in that location?

And why had the remains been discovered in circumstances that later forensic experts considered suspicious?

The Forensic Investigation

The investigation changed dramatically after forensic specialists examined the remains.

Experts from Kyungpook National University concluded that the skull injuries of at least three boys were consistent with intentional trauma.

One skull in particular displayed distinctive damage that the forensic team believed could not be explained simply by natural decomposition.

The experts therefore concluded that the children were likely victims of homicide.

This was a crucial turning point.

The case was no longer simply about five children who had disappeared and possibly died from exposure.

It became a murder investigation.

The Skull Injuries

One of the most disturbing aspects of the case was the damage found on several skulls.

Forensic investigators reported injuries that appeared to have been caused by blows from a hard or sharp object.

Contemporary reporting described damage involving depressions, cracks and holes.

The exact murder weapon was never definitively identified.

This distinction is important:

The forensic findings supported homicide, but they did not identify the killer or conclusively establish the exact weapon.

Some later internet theories have claimed a specific tool was used.

Those claims should not be presented as established fact.

The Burial Question

Another important issue involved the condition and location of the remains.

Forensic investigators noted that the bones were not simply scattered across the mountain.

The remains appeared to have been gathered together.

This raised the possibility that the bodies had been deliberately concealed.

Some investigators therefore believed that the boys had been killed and buried at the location.

But the precise sequence of events remains unknown.

We do not know exactly where the boys were killed.

We do not know precisely when they died.

We do not know whether they were killed at the discovery site.

And we do not know who transported or concealed their remains.

A Strange Detail: The Clothing

The condition of the children's clothing became another point of debate.

Some investigators and observers questioned why the clothing appeared relatively well preserved despite the passage of more than 11 years.

There was also discussion about the absence of obvious blood staining on the clothing despite the reported skull trauma.

Forensic experts explained that blood evidence can disappear over long periods, but the condition of the clothing remained one of the questions surrounding the case.

It did not, however, provide a definitive alternative explanation.

Moss and Environmental Evidence

Investigators also reported traces of moss in the skulls of two of the boys.

This was interpreted as evidence that the remains had at some point been exposed to environmental conditions.

Investigators also found traces of a small campfire near the area.

These findings contributed to the reconstruction of what may have happened to the bodies, but they did not identify a perpetrator.

The Military Base and Shooting Range

One of the most discussed geographical details is that Waryong Mountain contained military facilities.

Contemporary accounts describe an army base and a shooting range in the surrounding area.

Bullet casings and bullets were also reported near the remains.

However, the nearby military unit reportedly said that no training had been scheduled that day because March 26, 1991 was an election holiday.

The existence of ammunition-related material therefore became another point of speculation.

It should not be presented as proof that the military was involved.

There has never been reliable evidence establishing military personnel as the perpetrators.

The “Horrendous Scream” Account

Another detail often discussed in connection with the case is the testimony of a child who reportedly said he heard a terrible scream from the mountain on the day the boys disappeared.

The families later criticized investigators for allegedly failing to give sufficient attention to some witness testimony, including this account.

Whether the scream was connected to the boys has never been established.

Why Were the Bodies Not Found Earlier?

This is arguably one of the biggest unanswered questions.

The mountain had been searched repeatedly.

Police and volunteers searched the area soon after the boys disappeared.

Yet their remains were discovered more than a decade later.

The discovery site was close enough to the area that many people naturally questioned how it could have been missed.

Police later explained that earlier searches had focused heavily on ponds, streams and other areas and that the exact location of the remains had not been thoroughly searched in the same way.

The families strongly disputed this explanation.

Woo Jong-u, the father of Woo Cheol-won, said he had been in a police helicopter searching the mountain shortly after the disappearance.

The question of whether the remains were somehow overlooked, concealed more effectively than previously believed, or placed there later remains one of the enduring mysteries.

The 1996 Burial Claim

In 1996, a professor associated with KAIST who had studied criminal psychology reportedly claimed that the boys had been buried beneath the home of Kim Jong-sik.

Police investigated the claim and excavated the property.

Nothing connected to the missing boys was found.

The professor was later fined for defamation.

This is an important example of why many claims surrounding the case should be treated cautiously.

The 2002–2003 Investigation

After the remains were discovered, investigators initially considered accidental death and exposure.

But forensic examination shifted the investigation toward homicide.

In January 2003, the Kyungpook National University forensic team publicly stated that the boys were likely murdered.

The investigators said that at least three skulls displayed damage consistent with blows from a metal object or tool.

Police reopened the investigation.

Hundreds of tips concerning possible suspects followed.

But none produced a confirmed killer.

Was a Bullet Involved?

There has been confusion surrounding reports of holes in the skulls and bullets or casings found near the remains.

One early forensic examination specifically reported that a hole in one skull did not appear to be a bullet wound.

Later reporting has also repeated claims about gunshot-related evidence.

Because the remains were heavily deteriorated and forensic interpretations developed over time, it is safer to say:

The case involved reports of ammunition-related material and unusual skull damage, but there is no established public conclusion that the boys were shot.

The established forensic conclusion was that several skull injuries were consistent with violent trauma.

Theories About the Killer

Theory 1: A Random Adult Attacker

One possibility is that the boys encountered an adult on the mountain who attacked them.

The theory fits the forensic conclusion that the deaths involved violence.

But there is no identified suspect, eyewitness account proving such an encounter, or established motive.

Status: Possible, but unproven.

Theory 2: Older Local Students

Another theory suggests that the boys encountered older teenagers or students near the mountain.

This became especially prominent because of the presence of schools and other facilities around the area.

The theory proposes that an argument or confrontation may have escalated into violence.

Again, there is no proven perpetrator.

Status: Unproven theory.

The Vernier Caliper Theory

One of the most famous modern theories appeared online in 2022.

An anonymous user on the Korean online community Nate Pann claimed to know what happened.

The post alleged that vernier calipers were used as murder weapons.

It also claimed that the boys had encountered high-school students who had been inhaling glue and that the boys were killed because they might report what they had seen.

The theory received considerable attention online.

But there is a major problem.

Daegu police said that reports about vernier calipers had already existed around the time the remains were discovered in 2002.

Forensic investigators reportedly concluded that the skull injuries did not match such a tool.

Therefore, the viral 2022 claim did not solve the case.

Status: Internet theory; not established evidence.

Theory 3: The Military

Because Waryong Mountain contained military facilities and a shooting range, some people have speculated about military involvement.

The presence of bullets and casings near the remains has also fueled this theory.

However, there is no established evidence proving that military personnel killed the children.

The nearby military unit reportedly stated that no training had been scheduled on the day of the disappearance.

Status: Speculation, not an established conclusion.

Theory 4: The Boys Were Accidentally Killed

Another possibility is that the boys encountered an accident or dangerous situation.

This was particularly relevant before forensic investigators concluded homicide.

However, the reported skull trauma made a simple accidental-death explanation difficult to reconcile with the forensic findings.

Status: Largely superseded by the forensic homicide conclusion.

Theory 5: They Died of Hypothermia

This was the original police theory after the remains were discovered.

The weather was cold enough for exposure to be considered.

However, forensic investigators later concluded that the skull injuries indicated homicide.

Therefore, hypothermia is no longer the leading explanation for the deaths.

Status: Initial police theory; contradicted by later forensic findings.

Theory 6: The Bodies Were Moved

Because of questions surrounding the search and the condition of the remains, some people have wondered whether the bodies were originally hidden somewhere else and later moved to Waryong Mountain.

This possibility has never been established.

Environmental evidence, including moss and the condition of the remains, has been discussed in relation to where and how long the bodies were exposed.

But there is no definitive public evidence proving that the bodies were transported to the mountain years after the disappearance.

Status: Unproven hypothesis.

Theory 7: Kidnapping for Ransom

The ransom calls during the early investigation naturally generated kidnapping theories.

However, no credible evidence ever established that the children were kidnapped for ransom.

The calls appear to have been hoaxes.

Status: No supporting evidence.

Theory 8: UFOs and Other Extraordinary Explanations

During the 11-year search, some bizarre theories circulated, including UFO abduction claims.

These stories became part of the folklore surrounding the case.

There is no credible evidence supporting them.

Status: Unsupported.

What Did the Families Believe?

The families have consistently rejected the idea that the children simply wandered into the mountain and died naturally.

They have repeatedly questioned the original police investigation.

Their concerns included:

• The boys knew the mountain.
• The discovery location was relatively close to their neighborhood.
• The area had been searched.
• Some witness testimony was allegedly not adequately investigated.
• The skull injuries indicated violence.
• The remains appeared to have been concealed.

The families have also criticized what they regarded as failures during the early investigation.

In 2005, the families sued the government over the handling of the case.

The court ultimately ruled that there had been no legal violations in the police investigation.

The 2004 Funeral

The families delayed the final funeral while investigators continued examining the remains.

On March 26, 2004, exactly 13 years after the disappearance, the boys' funeral was finally held.

The remains were cremated.

According to later reporting, the ashes were scattered in the Nakdong River, while the families retained the skulls in the hope that future forensic advances might eventually help identify the killer.

The Statute of Limitations

The case became even more complicated because South Korea's murder statute of limitations at the time eventually expired.

The relevant deadline for the Frog Boys case was March 25, 2006.

This meant that under the law then applicable, prosecution could no longer proceed after that date.

However, South Korea later abolished the statute of limitations for certain murders in 2015.

This did not automatically revive every old case, and legal applicability depends on the specific offense and circumstances.

For the Frog Boys case, contemporary reporting continues to describe the old prosecution deadline as having expired.

The Case Was Reopened

In 2019, the Daegu Metropolitan Police Agency renewed the investigation.

National Police Agency Commissioner General Min Gap-ryong visited Waryong Mountain and publicly promised to investigate the case again from the beginning.

Police said they intended to use modern forensic technology to re-examine preserved evidence.

The investigation team also sent dozens of preserved pieces of evidence to the National Forensic Service for examination.

Police stated that they would not limit the investigation to one particular theory.

What Happened After the 2019 Reinvestigation?

The renewed investigation produced renewed public interest.

Police reviewed old records and evidence.

They received additional tips.

However, no decisive evidence identifying the perpetrator emerged.

The case therefore remained unresolved.

In 2026, Korean reporting confirmed that the Daegu police cold-case investigation was still continuing, including re-examination of evidence and case records.

The 35th Anniversary — 2026

March 26, 2026 marked 35 years since the boys disappeared.

A memorial ceremony was held at Waryong Mountain in Daegu.

Family members, local officials and residents attended.

The families continued to call for:

• A truth-finding committee
• A memorial hall
• Greater transparency concerning investigation records
• Modern forensic examination
• Continued efforts to identify whoever was responsible

The latest reporting confirms that the case remains unresolved.

What We Actually Know

After separating evidence from speculation, several facts are relatively clear.

Confirmed

1. Five boys disappeared on March 26, 1991.

2. They were between 9 and 13 years old.

3. They lived in the Daegu area and attended Seongseo Elementary School.

4. They went toward Waryong Mountain.

5. They were believed to be looking for salamander eggs.

6. A massive nationwide search followed.

7. Their remains were discovered on Waryong Mountain on September 26, 2002.

8. DNA and forensic investigation identified the remains as those of the five boys.

9. Forensic specialists concluded that at least several of the skull injuries were consistent with violent trauma.

10. No perpetrator was ever convicted.

11. The case remains unsolved.

12. Daegu police reopened/reinvestigated the case in 2019.

13. The investigation was still being reported as ongoing in 2026.

What We Do NOT Know

Despite decades of investigation, some of the most important questions remain unanswered.

Who killed the boys?

Unknown.

Why were they killed?

Unknown.

Where exactly were they killed?

Unknown.

Were they killed at the place where their remains were discovered?

Not definitively established.

What exact weapon was used?

Unknown.

Was one person responsible or more than one?

Unknown.

Were the military facilities connected?

No reliable evidence has established that they were.

Was the vernier caliper theory correct?

No. Police said earlier forensic examination did not support that weapon theory.

Why weren't the remains found during the original searches?

Still disputed and unresolved.

Why the Case Still Fascinates People

The Frog Boys case has remained powerful in South Korean culture for several reasons.

Five children disappeared together.

There was a massive search.

Their families spent years looking for them.

The country became involved.

Then, after more than 11 years, the children were found on the same mountain toward which they had originally gone.

Instead of providing closure, the discovery created new questions.

The case also became a symbol of the limitations of investigations before modern forensic technology became widely available.

The Human Side of the Case

It is easy for a decades-old mystery to become merely an internet story.

For the five families, however, it was never a mystery story.

It was their children.

The fathers spent years searching.

Some family members died without learning what happened.

Even decades later, surviving relatives continue to demand answers.

The 2026 anniversary reporting emphasized that the families are still seeking a full explanation and continue to request a renewed effort to uncover the truth.

The Frog Boys in Popular Culture

The case has influenced South Korean films, books, television programs and documentaries.

A 1992 film was made while the children were still missing.

The 2011 Korean film Children brought renewed attention to the case.

The story has also appeared in investigative television programs, including SBS's long-running investigative program Unanswered Questions.

The case has therefore remained part of South Korea's cultural memory long after the original search ended.

The Biggest Unanswered Questions

More than 35 years later, several questions continue to define the case:

Why did five children disappear together?

What happened between their last confirmed sighting and their deaths?

Why were several skulls damaged?

Why were their remains found in that particular location?

Why did the original searches fail to locate them?

Who had the opportunity to harm five children without being identified?

Was the killer familiar with the mountain?

Was the crime spontaneous or planned?

Were the children killed together?

Was one person responsible, or were several people involved?

These questions remain unanswered.

The Most Responsible Conclusion

The Frog Boys case should not be presented as a solved murder.

The strongest evidence indicates that the five boys disappeared in 1991, their remains were discovered in 2002, and forensic investigators concluded that several of the skull injuries were consistent with homicide.

But the identity of the perpetrator has never been established.

The popular theories — military involvement, older students, a random attacker, the vernier-caliper theory, kidnapping and other explanations — remain theories.

There is currently no publicly established evidence that allows one of these theories to be declared the solution.

That is what makes the Frog Boys case one of South Korea's most enduring cold cases.

Five children went into the mountains in 1991.

Eleven years later, they came back as remains.

And more than three decades later, the most important question still has no answer:

Who killed the Frog Boys?

Sources & Further Reading

For readers who want to investigate the case further, the following are useful reputable sources.

Korea JoongAng Daily

A detailed English-language investigation containing historical photographs, forensic findings, family interviews, the 2022 vernier-caliper claim and the 2019 reinvestigation.

Korea JoongAng Daily — Frog Boys Case Investigation

CNA — Channel NewsAsia

A long-form report containing interviews with family members and extensive background on the disappearance, search and theories.

CNA Insider — The Frog Boys Case

Yonhap News Agency

Yonhap has published historical and current Korean-language reporting on the case, including the 2002 discovery, forensic investigation, 2019 reinvestigation and the 2026 35th-anniversary update.

Yonhap — 35th Anniversary Update, 2026

Yonhap — 2019 Police Reinvestigation

Yonhap — 2002 Identification & Forensic Examination

The Korea Times

Useful English-language archive material covering the case and its cultural impact.

The Korea Times — Frog Boys / Missing Children Case .....