An elderly woman with impaired vision stumbles into vegetation between the side of a garage and a boundary fence. Unable to find a way out, and undetected by searchers, she succumbs to the elements and dies. Her body is eventually found eight days later, just 10 metres from the busiest street in town.

It was 2006 when 79-year-old Mabel Jamieson went missing in Rotorua. Detective Senior Sergeant John Wilson, a search and rescue specialist, was one of the team looking for her. They covered 2500 properties near where she was last seen, making it one of the biggest suburban searches in the country.

The sad outcome made a deep impression on John, who knew that Mabel’s chances of being found, and surviving, would have been exponentially better if she was wearing a tracking device: “She would have been found in two hours instead of eight days.”

It was the catalyst for him to seek a practical way of providing a radio frequency device that could be used by vulnerable people such as Mabel.

In consultation with community groups, Alzheimers NZ and manufacturers of location technology, he set up the WanderSearch Charitable Trust in Rotorua in 2007, which now supplies up to 70 tracker devices to people in the region who are at risk of going missing.

While many of the initial recipients of the devices, which come in pendant, wrist and key-ring models, are people with dementia, they are also valuable for those with head injuries and people with autism.

The WanderSearch (also known as WandaTrak) programme is spread throughout the country, administered by trusts, Alzheimer’s groups and search and rescue organisations.

Search and Rescue NZ data notes that over six months of Police SAR callouts in 2019, the mean duration for finding a WanderSearch-device wearer was 1.8 hours with a maximum of six hours. For those who did not have a device, the mean duration was 4.7 hours and a maximum of 14 hours.

“The overwhelming thing about this technology is that it gives families such huge peace of mind,” John says. “When you have a wanderer, families are in a constant state of siege, always wondering when it’s going to happen again. As soon as you hang that pendant around their loved one’s neck and turn it on, it’s like a huge weight is lifted off them.”

The time-saving benefits for police are also significant. “You can put out two cars initially with four people who drive around the city until they pick up a ping. If that was a non-pendant job, you’d have to set up a management team, send someone to where they were last seen and do a 200-metre search of every section around that point. It’s resource intensive.”

Searching in urban areas is more complicated than in the bush, he says, where generally the person you are looking for is the only one there. “When you search a built-up area, you’ve got the whole population of that area interfering with your search.”

Poor Mabel was lying near the busiest street in Rotorua “with the whole population of Rotorua driving past”. Now, John says, when you find a missing person, “it’s not a fluke, it’s science… a lot of work can be alleviated with a little bit of technology”.

This year, John’s search and rescue work over 23 years was recognised with a New Zealand Search and Rescue Certificate of Achievement for Support Activity, presented to him in May at the NZ Search and Rescue Awards.

His WanderSearch initiative is just one of his achievements, sitting alongside his work as the Rotorua Police search and rescue co-ordinator, deputy chair of Rotorua LandSAR, setting up Water Rescue Squads in Rotorua and increasing the efficiency of helicopter rescues over water.

Last year, he negotiated an agreement with Tūhoe to host a district search and rescue exercise at the culturally and historically significant location of Maungapōhatu in Te Urewera, which led to Ruatāhuna residents expressing an interest in joining LandSAR.

As word of WanderSearch has spread, and with dementia on the rise, referrals for those who might benefit from it are increasing, John says.

“In Rotorua, if cops on the frontline encounter a wanderer and they haven’t got a pendant, they’ll put a referral through straight away.”

The pendant, or whatever form the transmitter is in, is a sealed unit that is turned on with a magnet. It transmits a signal on a radio frequency that can be detected by a handheld aerial.

Each device has its own radio frequency number associated to the person using it. The devices are small and unintrusive and the battery can last for six months or more.

When a person with a WanderSearch (or WandaTrak) device goes missing and police have been alerted, the signal from the device can be picked up from up to eight kilometres away from the top of overlooking hills. On flat ground, it can be picked up from about one kilometre away using a handheld aerial.

WanderSearch radio frequency devices are old technology compared with GPS, which has the advantages of being self-managed and only needs a working watch, but the battery life of GPS devices is only a few days and it relies on the cellphone network.