When they finally caught up with him, the killers of conservationist Esmond Bradley Martin knew he had no chance of escape or alerting anyone.
It was a Sunday afternoon, February 4, 2018. His wife, Chryssee Perry, a conservationist too, had gone for a meeting - and Martin, a US citizen, was home alone.
The back gate that opened into the bushes was left open, perhaps by the planners or killers. The padlock was also missing.
Detectives found the remote controlled panic alarm unit attached to a silver chain and that was always at Martin's bedside, under the conservationist's bed.
While this was noted by initial investigators on the evening that Martin's body was found, it later disappeared and has never been accounted for.
But more seriously, the killers of one of world's best known investigators into the ivory and rhino horn black market has never been apprehended.
The motive, too, has never been known. Everyone agrees this was no robbery gone wrong. It perhaps was a premeditated killing.
Martin's wallet was in his jacket pocket with Sh11,000. His watch, with a black strap, was left on the table while the mobile phone was in another pocket.
There could only be two motives - to stop his work as an investigator; or somebody who was eager to grab Martin's Sh1 billion property in Karen, Nairobi, where he owned 20 acres.
Originally belonging to scouting movement founder Lord Baden Powell, Martin was the third owner of the piece that was being eyed by real and potential grabbers. He had built a magnificent house here
Apart from the land, Martin, then 75, was a celebrity investigator obsessed with tracking down illegal ivory and rhino horn traders and poachers.
For more than 30 years, he had been on their trail, exposing them and unravelling their international networks.
With his colleague Lucy Vigne, they had penetrated the most dangerous hideouts of ivory traffickers, posing as dealers in areas controlled by gangsters and blood-thirsty mobs.
Around 11am that Sunday morning, Martin had left his Mutamaiyu Road house in Karen for a lunch date at Nairobi National Park.
He had asked the cook to prepare packed lunch and left with his driver.
His wife of 50 years, also left home around 2pm for Nairobi's animal orphanage, where she was a volunteer.
Shortly after 2pm, the cook switched on the electric fence, locked the back door and retired to the servant quarters until 6pm when he returned to make dinner.
When he arrived in the house, he noticed the electric fence had been switched off.
That was odd since the fence was always on during the day.
As a former United Nations Special Envoy for Rhino Conservation and as an undercover investigator on the black market, Martin had many enemies and like Icarus in the Greek mythology, he always flew too close to the Sun.
It was due to his work that China moved to ban the rhino horn trade in the 1990s and the domestic sales of ivory later on.
That month, Martin - a graduate of Liverpool and Arizona universities - had just returned from a research trip in Myanmar where he hobnobbed with ivory traders, noting retail prices, and examining the quality of carved items.
He was to compile a report for Save The Elephants.
"We ascertained the current demand for raw and worked ivory and what sells the most and to whom. We also watched the production and sales of substitute ivory and alternative products," Martin wrote in a final report, co-authored with Ms Vigne.
According to the report that was released posthumously, the ivory trade in China was slowing down.
It is not clear what time Martin returned home after his meeting. While the property has a fence and a steel gate, detectives had been told that this was only locked with a padlock at night.
The wrought iron gate had letter "M" designed on top, perhaps an indicator of the stylish aristocratic life that Martin lived in this Georgian House whose white exterior gave it an 18th century look.
New York Times writer Charles Homans gave the best description of the man.
"He had the mannered, patrician eccentricities of a Wes Anderson character: a dandelion shock of hair that had gone snow white by middle age, tailored suits - from Dunhill in New York and later Savile Row shops - that he wore even when he was doing fieldwork in Yemeni souks or Laotian night markets," Homans wrote.
Stabbed several times
Martin was rich. He was the great grandson of US steel millionaire Henry Phipps, who was a business partner of philanthropist Andrew Carnegie.
He opted to settle in Nairobi with his wife and had at first started writing scholarly history papers until he was lured into the ivory trade research by the World Wildlife Fund and the International Union for Conservation of Nature and Natural Resources.
What was intriguing about Martin's killing was that there was no forced entry into the house - meaning whoever murdered him simply opened the unlocked door.
Martin's wife told detectives that his vehicle was parked outside when she returned home some minutes after 6pm.
She alerted Martin with " I am back" . She then headed to the library on the ground floor of the building as there was no response.
Chryssee then went upstairs, hoping to find her husband at the study. He was not there.
It was getting dark and she went to her bedroom - they slept in separate rooms - and took a nap only to be awoken by the cook who was entering the house through the back door.
"Have you seen Martin?" she is said to have asked.
The cook had not - and that set the alarm bells. She then went to check Martin in his bedroom.
With his face down and in a pool of blood, Martin lay on the carpet motionless. Dead. It was 6.45pm.
Whoever killed Martin had gagged his mouth with a tie and stabbed him several times in the neck.
The killer appeared not to have been interested in Martin's money.
Message on the phone
On the lounge desk adjacent to the bedroom was some foreign currency and Martin's debit card, which would not have escaped a robber's eye.
The only place that was disturbed was the green steel filing cabinet. It is not clear what documents it contained.
An injured Martin appeared to have stood some metres from this cabinet as there were blood droplets on the floor. The key was left in the cabinet lock.
There was a message on his phone, which seemed to indicate that somebody was conversing with Martin about land.
But whether this is a line detectives will pursue in their investigations is not clear.
The New York Times said the murder was "linked to a property dispute" and in 2018, a local publication reported that there was an attempt at the land registry to grab the property.
Detectives said they were questioning some people.
Among conservationists, the unexplained death of Esmond Martin continues to be a reminder of unsolved murders in Karen - where prime land owned by expatriates is usually targeted.
It could also have been the work of the ivory gangs or somebody who had unfettered access to Martin - an inside job.
Whichever of these, Martin's death was brutal - at a time he had put his life on the line to save African elephants.
On the third anniversary of his death, the question remains: who killed Esmond Martin and why?
Will the murder ever be resolved or is this another typical cold case? Only time will tell.