Desert Secrets: How an 11-Year-Old Mystery in Joshua Tree Was Finally Solved

Joshua Tree National Park is a place of beauty and danger — an unforgiving landscape where people can vanish into the vastness and never be found. For over a decade, the disappearance of Marcus and Jenna Dinger haunted their families, the San Bernardino County Sheriff’s Department, and the tight-knit community that followed every turn in the case.

On October 5, 2011, the Dingers — Marcus, 42, and Jenna, 37, seven months pregnant — left for a “babymoon” camping trip in the park. The last photo they sent to Jenna’s sister, Khloe, showed them smiling in front of a lime green tent with the white bulk of their camper van behind them.

A day later, both were gone.

Theories swirled. Search teams combed the park for weeks. Law enforcement speculated that Marcus — under mounting financial pressure — had killed his wife and fled. But as the years passed, no evidence emerged to prove it.

Then, in late summer 2022, a hiker stumbled upon a shallow grave in a remote corner of the park. What investigators uncovered in the months that followed shattered the old theory and revealed a chilling truth: the Dingers had been murdered, their deaths tied to a secret prospecting operation and a man who had evaded justice for 11 years.

The Last Night in the Desert

The Dingers had planned their trip as a final getaway before their baby arrived. They were seasoned campers. Their van was equipped with a custom-built sleeping area, a kitchenette, and all the supplies they could need.

On the evening of October 5, Jenna texted Khloe:

“All set up for the night. The desert is beautiful. Love you.”

When noon the next day passed without a check-in, Khloe’s unease grew into panic. By nightfall, she had called park rangers.

Two rangers reached the campsite after dark. What they found was unsettling:

The van was locked, everything inside perfectly in place.

The tent was zipped, sleeping bags neatly laid out.

Wallets, cash, credit cards, and Jenna’s prenatal vitamins sat untouched inside the van.

Only the couple, the clothes they were wearing, and Marcus’s main cell phone were missing.

There was no sign of a struggle. No footprints leading away.

From Search to Suspicion

The San Bernardino County Sheriff’s Department launched an intensive search. Helicopters scanned from above, ground teams fanned out, and scent dogs combed the area.

The first crack in the idyllic portrait came from the financial crimes unit: Marcus was deeply in debt to high-interest lenders. Investigators theorized he might have killed Jenna and fled.

Two days later, a gas station attendant 100 miles from the park reported seeing a man matching Marcus’s description buy gas, a burner phone, and a paper atlas. It seemed to confirm the fugitive theory.

Khloe rejected it outright. She described Marcus as a devoted husband excited to become a father. Still, with no other leads, law enforcement focused on finding him — as a suspect, not a victim.

The search fizzled. The van was impounded, the case went cold.

A Hidden Compartment and a Strange Clue

In 2017, six years after the disappearance, an inventory of the impounded van uncovered something no one had seen before:

A hidden compartment in the cabinetry.

Inside, a sealed waterproof tube containing geological survey maps.

The maps were detailed surveys of a remote sector of Joshua Tree, annotated with cryptic notes about mineral deposits: “pegmatite dykes,” “possible monazite.”

At the time, investigators could not make sense of them. The theory that Marcus had fled seemed incompatible with the idea of a prospector’s maps. With no concrete lead, the discovery was logged and shelved.

The Grave in the Sand

On October 12, 2022, hiker Derek Vincent was exploring a remote area when he noticed disturbed soil near a boulder cluster. A glint of white caught his eye. Brushing away sand, he uncovered human ribs.

Forensic archaeologists excavated the site and found:

A nearly complete adult female skeleton in a seated position.

Within the pelvis, the delicate bones of a fetus.

Dental records confirmed the adult was Jenna Dinger.

The burial site was miles from the campsite — in the same remote area marked on Marcus’s hidden maps.

The Breakthrough

Detective Miles Corbin, reviewing the old file, cross-referenced the GPS coordinates from the grave with the geological maps. It was a perfect match.

Forensic examination of Jenna’s bones revealed something unusual: tiny particles of metallic dust embedded in the neck vertebrae. Testing identified it as thorite, a rare earth mineral found in only a few North American locations — one of them being the sector of Joshua Tree where Jenna was buried.

Investigators concluded the burial site was no accident. Marcus had gone there deliberately — and someone else had been there with him.

From Fugitive to Victim

Tracing Marcus’s debts led to a name from the original file: Leland Croft, his former business partner. In 2011, Croft had called in debts Marcus owed, sparking a bitter legal dispute.

Croft, it turned out, was an amateur geologist with a passion for rare earth minerals. His records showed purchases of prospecting gear and subscriptions to mining journals. Investigators now believed the geological maps were Croft’s, hidden in Marcus’s van.

The new theory: Marcus discovered Croft’s illegal prospecting operation inside the park. The “babymoon” trip was a cover for Marcus to confront Croft or gather evidence.

The Gas Station Ruse

The gas station sighting that fueled the fugitive theory was re-examined. Surveillance footage showed a man who resembled Marcus — but also Croft. Investigators now believed Croft staged the sighting to throw suspicion onto Marcus after killing him and Jenna.

The Interrogation

In 2023, Corbin and his partner found Croft in Oregon, running a hardware store.

At first, Croft was calm, dismissing the maps as one of Marcus’s “phases.” But when confronted with the thorite evidence and a bootprint from inside the van matching his preferred brand of geological boots, his composure cracked.

“He wasn’t supposed to bring her,” Croft whispered.

He confessed:

He had lured Marcus to the site under the guise of resolving their dispute.

An argument escalated, and he killed Marcus with a rock hammer.

Jenna, who had seen it, became his second victim.

He buried Jenna in a pit and hid Marcus’s body in an abandoned mine shaft.

The gas station trip was staged to frame Marcus.

Finding Marcus

Croft’s confession led search teams to a cluster of abandoned mine shafts. Using drones equipped with cameras, they found skeletal remains 150 feet down one shaft.

Marcus Dinger had been found.

Justice and Aftermath

Croft was convicted of two counts of first-degree murder and sentenced to life without parole.

For Khloe, the verdict brought closure but no joy.

“It doesn’t bring them back,” she said. “But now, finally, we know.”

Lessons from the Case

The Dinger investigation is now studied as an example of:

How early assumptions can derail a case.

The value of re-examining evidence with new technology.

The importance of persistence in cold case work.

For 11 years, the desert kept its secret. In the end, it was a combination of human curiosity, forensic science, and dogged police work that forced it to give the secret up.

Beneath the shifting sands of Joshua Tree, the truth had waited — patient, silent, and damning.