KUALA LUMPUR: On this day nine years ago, 239 people boarded Malaysia Airlines (MAS) flight MH370 at the Kuala Lumpur International Airport (KLIA) for Beijing, China.
There was nothing to indicate that it would be the last time they would ever be seen again.
What happened next has been well-documented. Some 40 minutes into what should have been a six-hour flight, the aircraft's transponder was switched off and the plane veered from its course.
Efforts to locate the aircraft led to the formation of at least two committees — the Malaysian International Civil Aviation Organisation (ICAO) Annex 13 Safety Investigation for MH370 and the police's Criminal Investigation Department (CID) MH370 task force.
Among those involved in the operation was Datuk Mohd Khalil Kader Mohd, who was the MH370 lead Criminal Investigator.
For the first time in nine years, Khalil, now retired, shares his story on how his 25-man team worked to uncover possible criminal elements behind what has become the world's biggest aviation mystery.
A MONUMENTAL TASK
Khalil said when Datuk Seri Hadi Ho Abdullah, who was then Federal Criminal Investigation Department (CID) chief, told him that he was appointing Khalil as the lead criminal investigator for the case, his reaction was initially one of trepidation.
"I knew nothing about airplanes. I asked Hadi, 'do we have any other candidates (to lead the team?' He replied, 'No, we pick you, so you proceed," he said.
Khalil said he faced tremendous pressure and stress, handling countless briefings, fielding calls every hour and returning home at 3am every day for three months.
However, he said it was nothing compared with the weight carried by the next-of-kin.
"They went through a lot more. We did our best to understand what happened and where the plane was. Unfortunately, it has yet to yield results."
He said the MH370 CID task force was formed to investigate possible criminal acts, which could have led to the aircraft deviating from its original path and disappear.
The probe was conducted under Section 130C of the Penal Code, to establish any act of terrorism.
Investigators, he said, had zoomed in on four main aspects — hijack, sabotage, personal and psychological problems.
The focus of their investigation centred on 12 main components — to establish MH370's flight path, fuel and airworthiness, technical crew (pilot and co-pilot), the 10 cabin crew, 227 passengers, the Iranian passengers with stolen passports, maintenance and ground crew, cargo, closed-circuit television camera (CCTV) recordings and relevant witnesses.
He said to effectively investigate the case, his team, comprising the best investigation officers nationwide, were given a crash course on aircraft mechanism.
"We needed to understand what transponders are, radars and others.
"MAS engineers taught us the mechanics from the nose to the tail. In the end, we became 'mini engineers'," he said.
DEALING WITH THEORIES
Khalil said the investigation was one of the most thorough probes he had been a part of in his 40 years of service.
He said apart from managing expectations, not just from Malaysians but also from China, which made up the bulk of MH370's passengers, they also had to deal with the various theories raised.
Some, he said, ranged from plausible to the ridiculous.
"Those shared by the professionals were helpful but nevertheless, we were obligated to investigate all the theories.
The theories included supposed sightings of debris in the Indian Ocean, as well as how a shipment of mangosteens on MH370 could have mixed with a cargo of lithium batteries, creating a 'flying bomb' onboard.
He said they checked out this theory, from vehicle used to transport the cargo, and even inspecting the plantations in Muar, Johor.
"We even inspected the packing process. I personally travelled to China to inspect the records to establish that yes, this was not the first time that mangosteens were exported there," he said.
He said they concluded that the items were in separate cargoes, sealed properly according to international standards and could in no way have mixed onboard.
On the theory that MH370 had actually landed at the 'secret military base' at Diego Garcia, Khalil said their probe was only based on existing data and facts.
PILOT SUICIDE
Among the enduring theories was that the pilot, Captain Zaharie Ahmad Shah, had hijacked the aircraft.
This was based on the assessment that the transponder was deliberately turned off, and that MH370 had made a deliberate air turn back in the South China Sea headed towards Penang, Zaharie's hometown.
Reports also claimed that data retrieved from Zaharie's flight simulator at his home showed a similar flight path to the route flown by MH370.
Khalil said their forensic investigations indicated that the similarity was irrelevant.
"We checked his background. We questioned his friends, none of whom gave negative (statements).
"It meant that he was very friendly, humble, a family man, and jovial, that was what we recorded," he said.
Khalil said they also scrutinised numerous CCTV recordings of Zaharie's movements at the airport and workplace, engaged psychologists and even examined the books he read.
"Basically, there was no ground to support the (pilot suicide) theory. All I can say is that this remains inconclusive until we find the aircraft," he said.
In 2017, the Australian Transport Safety Bureau (ATSB) published details on data extracted from Captain Zaharie's personal flight simulator.
The details were contained in a 440-page final report on the unsuccessful search for MH370.
The report said six weeks before the accident, the pilot-in-command had used his simulator to fly a route, initially similar to part of the route flown by MH370 up the Straits of Melaka, with a left-hand turn and track into the southern Indian Ocean.
"There were enough similarities to the flight path of MH370 for the ATSB to carefully consider the possible implications for the underwater search area (southern Indian Ocean)," it stated.
IRANIANS WITH STOLEN PASSPORTS
In the early phases of the disappearance, concerns were sparked over the role of two Iranians onboard MH370, who had used passports reported stolen in Thailand.
Khalil clarified that the duo — Seyed Mohammed Reza Delavar, 29, and Pouria Nourmohammadi, 18 — were actually supposed to have boarded an earlier flight.
Nourmohammadi was reportedly making his way to Germany to seek asylum and reunite with his mother.
"The family members bought the passports for these two to migrate.
"They were supposed to board an earlier flight, before MH370, but they missed it.
"So they bought another ticket, which was for MH370," he said, adding that they met with the duo's parents for clarification.
TRANSPARENCY POSER
Khalil also addressed criticism that Malaysia was not transparent in its findings, arguing that the country isn't the only one probing the incident.
"This question should be directed to the Transport Ministry, not the police. It is not fair for me to comment but I don't understand why they would claim Malaysia is not being transparent when the investigation committee comprised not just Malaysians.
"The committee is represented by experts from other countries, led by Australia (ATSB).
"So what is it that we haven't been transparent about? I think Malaysia has done its best," he said, adding that intelligence authorities from other countries had also probed the backgrounds of MH370 passengers.
He said the investigation has never been closed.
"The investigation paper remains open until new evidence arises, at which point we would proceed with the probe," he said.
Khalil said in any criminal investigation, two elements must established — the act and the intention.
"We have to look at the acts — air turn back, transponders switched off. With these facts, we then have to prove the intention.
"In the case of MH370, we have the acts. However, it has not led to any conclusion that can help establish any criminal activities.
"But the main evidence, the aircraft itself, remains missing. This is why we cannot conclude the investigation," he said.
Khalil said while he was satisfied that they have done all they can in the probe, he was nevertheless saddened that the aircraft, as well as its black box, remain missing.
"The other day, I visited my parents' graves in Seremban. While I was there, I was approached by someone who was visiting his cousin's grave.
"He said he knew me because I was in the newspapers talking about MH370.
"He told me that his close friend was on the plane. He asked me, 'Please, can you share just a bit on where the airplane is, what actually happened?'
"I felt sad. I wept. I told him, let's pray that we will find the plane. That is my hope.
"With the amount of human knowledge that we have right now, there is nothing else we can do.
"We can however hope that God will help us to find the plane," he said.