In the weeks leading up to August 29, 2016, Mark Tromp had been suffering from severe anxiety. He was completely consumed with the idea that an unnamed group was watching his family, planning to destroy them.
51-year-old Tromp and his wife, Jacoba, 53, had spent years building a redcurrant farm and earthmoving business in Silvan, east of Melbourne. Their adult children, Riana, 29, Mitchell, 25, and Ella, 22, all worked the farm.
Because they were a close-knit family and worked seven-day workweeks together on their Silvan berry farm, his panic infected his wife, Jacoba, and their adult children.
That day, their collective paranoia peaked. Mark convinced the family that their lives were in immediate jeopardy and that they needed to flee.
Initially, they pulled out their passports, looking to book an international flight. Mark then became terrified that the government or the unseen threat would easily track them to the airport and intercept them.
So they decided to escape by car, determining that a cash-only protocol would be best so they could not be traced. They packed in a frenzy and left in Ella’s Peugeot SUV, leaving a chaotic scene that alerted the authorities that something was wrong.
The family owned multiple vehicles, all left sitting in the driveway with the doors open and the keys in the ignition. The family also left the front door to their house unlocked.
Their rooms were in disarray, and financial documents were piled on the tables. It suggested that the parents had been frantically searching for something specific before fleeing.
Everyone also left their main mobile phones, credit cards, bank cards, and wallets at home. They carried only a large sum of cash and the clothes on their backs when they made their escape.
Mark and Jacoba’s son, Mitchell, was deeply sceptical about the sudden paranoia and panic, so he secretly smuggled his phone into the vehicle as they drove off. About 19 miles into the drive, when his parents realised he still had the phone, they erupted into panic.
Believing the device was a beacon being used by their pursuers, they forced Mitchell to roll down the window and throw it out of the moving car. For Mitchell, the experience of seeing his parents lose touch with reality was surreal. It felt like they were in a movie.
Virtually cut off from all communication, Mark took the wheel from Monday evening and drove north towards New South Wales through the night. Inside the vehicle, the tension was thick.
Their parents refused to stop at motels or for food or even use the highways, because they felt that was an easy way to get tracked.
The Initial Fractures
By the next day, the strain of this impromptu escape had begun to catch up to the group, fracturing the family.
They had driven for 500 miles overnight from Victoria when Mark stopped in Kelso. Having witnessed his parents’ paranoia intensify all night, Mitchell decided he had reached his limits.
He slipped away from the vehicle, walked to a train station, and began the journey back home. The remaining four, including Riana and Ella, continued from Bathurst to Jenolan Caves.
It was there among the limestone caves and the tourist trails that their two daughters decided to leave. Since they had no money or identification, they decided to steal a vehicle at the Jenolan Caves and drove south to Goulburn.
When they got to Goulburn, Ella and Riana used a pay phone to call emergency services. They officially reported their parents, Mark and Jacoba, were missing and acting erratically.
Shortly after they reported their parents, Ella and Riana had a panic-filled disagreement at the gas station. Ella was desperate to go back and said her main focus was to look after her horses.
Riana, though, was overwhelmed by psychological distress and being left without resources. After they separated, she wandered onto a highway and climbed onto the back of a stranger’s utility truck.
The driver heard an unusual kicking sound from the truck bed and pulled over, discovering Riana. She was in a completely catatonic and unresponsive state.
When he called the police, Riana manifested amnesia and was unable to tell the police her name, where she was from, or what year it was.
The Wednesday Encounter and Jacoba’s Recovery
On August 31st, Mitchell finally arrived home in Melbourne that morning after taking the overnight train, while the rest of the family remained largely unaccounted for.
That evening, in Wagaratta, a young couple playing Pokémon Go in their vehicle reported being followed by a vehicle that matched the description of Ella’s Peugeot. The driver apparently said he could barely see the following car’s headlights because it was so close behind.
When they pulled over, the pursuing Peugeot stopped as well. The driver stated that a man got out of the car, walked toward the road, then stood and stared at them before turning and walking into Merriwa Park, where he disappeared.
The vehicle did not appear to have any other occupants, and the couple called the authorities. Police arrived at the scene at 10 pm, and they identified the Peugeot as the same vehicle belonging to the Tromps.
The keys were still in the ignition. Officers brought in dogs to search the park, but there was no sign of Mark Tromp. Investigators also considered a break-in incident at Mike’s Cottage within the same area at the time.
They suspected that the unidentified man may have spent the night there, but this was never confirmed.
On Thursday, Jacoba Tromp was spotted wandering the streets in Yass, a town 350 kilometres north of Wangaratta. She was apparently trying to book a motel when hospital staff, alerted by someone who had helped escort her there, recognised her from the missing-person news alerts and called the police.
Doctors assessed Jacoba at the Yass hospital and determined that her mental health was not good. She was later transferred to Goulburn Hospital, where she was reunited with her daughter Riana.
Apparently, once Mark and Jacoba realised that their daughters had also vanished along with their son, they panicked, got back into the grey Peugeot SUV, and drove blindly through the night.
Rather than continuing north, they turned around and drove back south into Victoria. By the time that they reached Yass, their shared delusion had intensified to a critical level.
At some point in Wangaratta, they separated, and Mark continued on his journey to track down his daughters. Jacoba, highly detached from reality, left and boarded a public bus to flee the area on her own.
Mark drove on, ultimately tailgating the couple before coming to a stop behind them. He then proceeded on foot and disappeared into Merriwa Park, slipping into a state of further aggressive paranoia.
Mark Tromp is Found
Five days after the family fled their home, Mark Tromp was spotted by a passerby walking on the outskirts of Wangaratta at 5.30 pm. He was taken into custody for questioning and issued a mental health assessment.
When he was eventually released into the care of a family member, he gave an obscene gesture to the press waiting outside. His son Mitchell said he jumped for joy when he learned that his father had recovered safely.
In the days that followed Mark’s discovery, Mitchell and Ella spoke to the media, but they did not give a complete picture of what triggered the flight in the first place. Mitchell claimed it was a buildup of different everyday events and pressure.
Mitchell also expressed regret about leaving the family earlier, saying, “I thought getting out was the best idea at the time, but in hindsight I should’ve stayed and tried to help, bring them back around, try to talk to them some more.”
When pressed by the media on what triggered the events, Mitchell was cautious not to say too much. “There are a few [things]… there’s nothing that I know for sure, but there are possible things, but I can’t say at this stage because I’m not certain.”
Ella added, “It was all very confusing. I still feel confused. Mum and Dad’s minds weren’t in the best places.”
Police sergeant Mark Knight said it was the most bizarre thing he had ever seen in three decades on the job.
The Legal Ramifications
Despite the fact that none of the children or the parents got hurt, or that fleeing was not a crime, Riana and Ella did steal a vehicle.
Ella was charged with theft of a motor vehicle and possession of the proceeds of crime. She was bailed to appear at the Ringwood Magistrates Court in April 2017.
Riana also faced an identical motor vehicle theft charge. The charges were dismissed under Section 33 of the Mental Health Act in New South Wales. The provision excuses a person experiencing mental issues from criminal liability for the act.
With the vehicle owner’s compassion and permission, the police formally withdrew charges against Ella. This allowed her to avoid a criminal record or further consequences.
Even though the disappearance of the family led to exhaustion of police personnel and community rescue resources across two states, the authorities did not penalise or fine the family.
They were allowed to quietly return to their Silvan berry farm to undergo private psychiatric rehabilitation.
Mark’s Public statement
Mark Tromp broke his silence a week after his recovery in Wangaratta. He released a written statement through the police, addressing the community for the first time.
Apologising for the strain the search had placed on emergency services, he said, “I am conscious of the burden these events have placed upon our extended family, friends, and the community resources devoted to our aid.”
Mark also thanked the agencies involved in tracking down his family. “On behalf of our family, I express our deep gratitude to Victoria and New South Wales Police, as well as the health care professionals who have looked after our physical and mental well-being.”
In March 2017, seven months after the family left Silvan, the legal proceedings closed. By this time, the family had returned to the farm and resumed their previous life, including the redcurrant business.
Medical professionals and the police concluded that the family had suffered from folie à deux, or a shared delusion. This is a rare condition that entails an intense paranoid delusion spreading through a close-knit group.
Before the diagnosis was made public, neighbours and local farmers were stunned by the family. The Tromps were known previously as very stable and successful redcurrant farmers and contractors who worked long hours.
Sergeant Knight, who personally knew the family, stated that the case left him baffled. He also said they had no history of substance abuse or mental health problems.
The incident had captured the attention of true-crime enthusiasts and international media, who descended on the small town, looking to get to the bottom of things. Local business owners and farmers actively refused to speak to reporters and shut down media inquiries to give the family space to heal.
Rather than ostracising them, the community rallied around the Tromps with empathy. While the parents and Riana were hospitalised, local farmers stepped in to ensure their livestock were cared for and the berry farm carried on as usual.
The Unexplained Problem
What makes the Tromp case so unique is the absence of any villain. They were not fleeing an actual external threat, and no crime was committed against them before the trip.
The decision to leave passports, bank cards, and mobile phones was both good and crippling. On the one hand, they did not have the means to go far if they got into trouble. But the lack of funds and access meant reduced capacity to do more harm to themselves or to others.
The most consistent explanation offered by the family was the mounting financial pressure, which compounded the already present paranoia. As the family refused to reveal the exact trigger, the public came up with several theories.
For months, some locals suspected the family may have been accidentally poisoned by pesticides or heavy metals. Though the health authorities ruled this out, saying the farm used the same water supply as the rest of Melbourne.
Others became suspicious of the adult children, asking how they could so easily go along with their parents. This led to rumours that the family was hiding a real threat, but police confirmed no such threat existed.
If you’re interested in reading other eerie or unusual stories, explore our articles on the 2016 Creepy Clown phenomenon and Kim Ung-Yong.
