A retired U.S. Army veteran says his missing geologist son Daniel Robinson may be the victim of a crime based on evidence uncovered by the family's private investigator after police found his wrecked Jeep abandoned in a remote Arizona desert.

Local police, however, say they've found no indication of foul play, and David Robinson, who served two tours in Afghanistan, told Fox News Digital he hopes the Maricopa County Sheriff's Office intervenes.

"I didn't believe my son suffered a severe injury that caused him to kick out the sunroof, shred all his clothes off, hide in a tree, join a monastery and become a monk," said the father, who previously had a private investigator on the case. "So, I had to get a second opinion about that."

He said his son's Jeep traveled 11 miles after all the airbags deployed, and the investigator found signs someone besides police searched the missing geologist's bedroom after his disappearance. The family has also received ominous but unverified messages on social media, including a photograph of a man holding a gun who the anonymous sender claimed was the missing Robinson's killer.

MISSING ARIZONA GEOLOGIST DANIEL ROBINSON: A FATHER'S UNENDING SEARCH FOR HIS SON, ONE YEAR LATER

Daniel Robinson at National Park

Daniel Robinson in an undated photo provided by his father. (David Robinson II)

The elder Robinson issued a public call for help at CrimeCon 2023 in Orlando over the weekend, where he took the stage alongside the families involved in other high-profile disappearances, including travel blogger Gabby Petito, 22, and the 19-year-old self-made farmer Dylan Rounds. The families said law enforcement, which was slow to accept a missing person report for Petito, has been even slower to act on cases involving the two young men.

Buckeye Police in May publicly disclosed more than 120 pages of investigators' records in the Robinson case.

WATCH: U.S. Army veteran unveils concerning evidence in son's mysterious disappearance

In interviews with friends and family, detectives heard nothing about Daniel Robinson being suicidal or wanting to harm himself, according to police records. But he displayed some strange behavior in the days immediately before he vanished. 

The colleague who last saw him leaving a well site on June 23, 2021, told police he'd made strange references to driving 50 miles away to Phoenix to "rest." A day earlier, he texted a woman he barely knew but apparently had fallen in "love" with. She told him to leave her alone. And a co-worker told detectives Robinson cut his hair and talked about changing himself in other ways at breakfast in the days before he was last seen.

On July 6, 2021, police searched Robinson's apartment and found the common areas to be orderly but a mess in his bedroom.

"There was no indication of foul play," a detective wrote in a supplemental report, but there was also "no indication that Daniel had packed and planned a trip."

MISSING ARIZONA GEOLOGIST: NEW DETAILS RELEASED IN DISAPPEARANCE OF DANIEL ROBINSON

Daniel Robinson's jeep and Daniel Robinson

Daniel Robinson's crashed 2017 Jeep Renegade, left; Daniel Robinson in an undated photo, right. (Buckeye Police Department)

They found his computers and other valuables inside. According to his father, the family's private investigator found two suspicious signs — that Robinson's bedroom had allegedly been searched thoroughly by a third party and that someone had accessed his computer after he'd gone missing.

"The big mystery is where is Daniel?"

— Ted Williams, former D.C. homicide detective

"It could’ve been police," said Ted Williams, a renowned lawyer and former Washington, D.C., homicide detective. "And also a lot of times when individuals go missing, and individuals in the public find out they are missing — there are burglars, thieves, people who are nosy — who will try to go to the place where they lived, and they will go through the person's items in that place. That has taken place on numerous occasions."

Daniel Robinson with hard hat on

Daniel Robinson in an undated photo provided by his father. (David Robinson II)

GABBY PETITO CASE BRINGS RENEWED INTEREST IN FINDING MISSING PEOPLE, HIKERS

On July 19, 2021, a rancher located Robinson’s 2017 Jeep Renegade battered and rolled onto its passenger side in a ravine. The vehicle had front-end impact damage, a broken driver's side window and lost a piece of its roof. It was still in drive.

"My investigator found that there was a form of foul play there, and the vehicle was staged," David Robinson said.

Scene of Daniel Robinson crash

Daniel Robinson's crashed 2017 Jeep Renegade. (Buckeye Police Department)

Police found clothes, Robinson's phone and work computer inside. His wallet had no cash inside.

Despite extensive damage to the vehicle, there was no blood and no indications Robinson had spent "a considerable amount of time" at the crash site. Police found a stash of water bottles, but none were empty. They saw no tracks. However, investigators noted it had rained at least three times between when Robinson was last seen and when they arrived at his SUV.

Daniel Robinson with his father

Daniel Robinson and his father, David Robinson, in an undated photo provided by the family. (David Robinson II)

The elder Robinson told Fox News Digital Saturday that his private investigator believed the scene had been staged to look like a crash. According to the police report, the ignition had been cycled 44 times after the crash, a detail that an accident reconstructionist called an "unanswered anomaly." 

"There is insufficient evidence to scientifically connect the Jeep to another crash or support a theory the Jeep crash, as found, was staged," the reconstructionist wrote in a 15-page report. "The driver of the Jeep drove it into the ravine, and having rolled and unable to proceed further, abandoned the Jeep as it lay."

"[The private investigator] looked through the black box data and found that after the airbags deployment, the vehicle was driven 11 additional miles," David Robinson said. Police, however, provided several other potential explanations for the discrepancy between the odometer reading and the mileage total in the airbag data that would not involve driving the vehicle after the crash.

Daniel Robinson sitting on rock

Daniel Robinson in an undated photo provided by his father. (David Robinson II)

The private investigator, Jeff McGrath, who no longer works for the Robinson family, also told detectives that he found red paint transfer on Robinson's blue Jeep, indicating a crash with something red prior to arriving at the ravine, according to police records. The vehicle's history showed at least one prior crash, but it was not clear when the red paint transfer occurred.

The rancher who found the Jeep told police he didn't believe the vehicle had been there for the month that passed between Robinson's disappearance and the discovery of his Jeep.

In interviews with police, family members said it looked like Robinson's Instagram photos had been removed following his disappearance.

CLICK HERE FOR MORE TRUE CRIME FROM FOX NEWS 

"The big mystery is where is Daniel?" Williams told Fox News Digital. "Dead or alive, where is he?"

If Robinson had died in the ravine crash, his body would be there, he said. If he'd survived and wandered off, there'd be signs.

"The mystery in this case is who crashed the Jeep?" he said. "Was it Daniel or was it someone who staged the crash?"

David Robinson poses

Daniel Robinson in an undated photo provided by his father. (David Robinson II)

The father has been unsatisfied with the lack of answers more than two years after his son was last seen driving away from a job site.

Now, he's hoping the Maricopa County Sheriff's Office will get involved in the case, which is currently being handled by the Buckeye Police Department.

CLICK HERE TO GET THE FOX NEWS APP

Robinson is described as thin and below average height. He was born without a right hand.

The Buckeye Police Department is asking anyone with information to call 623-349-6411 or submit tips online at www.buckeyeaz.gov/crimetip.

The family also has a website with information on the case, pleasehelpfinddaniel.com.

Fox News' Stephanie Pagones contributed to this report.