It has now been over two years of theories, false leads, heartbreak, and investigation since the Malaysian Airlines flight 370 mysteriously vanished off the radar during a routine flight from Kuala Lumpur to Beijing with 239 passengers and crew aboard.

The March 2014 disappearance kicked off a multinational search effort, which initially ranged from China southward toward Australia. As the hope of finding survivors waned, the importance of locating the aircraft and finding answers to what, or who, was responsible for the disappearance waxed.

Soon one avenue of potential information may close: the joint Chinese-Malaysian-Australian search team announced Friday that they will likely suspend the search for the aircraft by the end of the year. But new information in a confidential document from the Malaysian police investigation emerged Friday, and may buttress theories that the pilot orchestrated the crash in a mass-murder-suicide.

The document, obtained by aviation specialist and journalist Jeff Wise of New York magazine, reveals that the plane’s captain Zaharie Ahmad Shah used his home flight simulator to create a flight route similar to the one that investigators now believe brought the flight to its tragic end in the south Indian Ocean.

According to the report, the FBI found six deleted data points in the Microsoft Flight Simulator X program that they flagged "of interest." When linked together, these data points show a flight path that moves northwest over the Malacca Straight before cutting south and heading down over the Indian Ocean toward Antartica.

There is significant similarity between that route and the one that investigators have deduced as the plane's final flight, based on hypothesis, flight data info, and several pieces of debris likely to have come from MH370.

The flight paths are not identical: the simulated route cuts further southeast toward Australia and ends some 900 miles south of the area that investigators have come to focus on, Wise reports. But the emergence of the information turns the public spotlight back on the 53-year-old pilot.

And the document is not the only piece of information that may implicate Capt. Shah.

Just before New York magazine released the documents, Paul Kennedy, project director at Fugro, the Dutch company leading the underwater search, voiced his opinion that the plane might be further south than searchers have believed. It’s a theory that would require a human hand.

"If it was manned it could glide for a long way," Kennedy told Reuters. "You could glide it for further than our search area is, so I believe the logical conclusion will be well maybe that is the other scenario."

The ocean search has focused on an area that authorities believe MH370 would have been gone down if it met an un-piloted end.

But the investigation, launched at the time of the disappearance, probed passengers, crew, Shah, and co-pilot Fariq Abdul Hamid for evidence of motive or involvement. And the early discovery that the plane’s communications system was disabled had seemed to suggest that the plane was either hijacked or its disappearance orchestrated by a pilot. Turning off that system requires a keyboard input and manually switching a number of cockpit controls in sequence.

Since that fateful night when controllers lost contact with MH370, Shah has moved in and out of prominence as a suspect and focus of public theorizing.

Public scrutiny focused around his potential links to Malaysian political opposition leader Anwar Ibrahim and the discovery of the flight simulator at his home – a development which led pilots to come out and tell the public, essentially – that’s not that unusual.

Parallels were also drawn between MH370 and the 1997 SilkAir Flight 185 crash, which was concluded to be a suicide mission by the pilot. There have been 13 cases of what appeared to be pilot suicide since 1976, according to the US Aviation Safety Network. The latest was the March 2015 crash of a Germanwings flight in France, killing all 150 passengers and crew.

But there was also outrage at theories implicating Shah: Shah’s friends and family came forward to defend him, and their accounts prompted the New York Times to characterize him as “a grandfather and veteran pilot widely respected by his colleagues,” who “brimmed with enthusiasm for flying, cooking and home repair hobbies.”

And while it became clear early on in the investigation that someone was in control of the plane when it went off-route, theories abounded that mechanical difficulties could have led the pilot to change course.

In a much-circulated opinion piece originally published in a blog by Chris Goodfellow, the Canadian pilot sets out his theory that fire caused the veer off-route, but also chastises the public fervor indicting Shah without proof. He wrote:

There is no point speculating further until more evidence surfaces, but in the meantime it serves no purpose to malign pilots who well may have been in a struggle to save this aircraft from a fire or other serious mechanical issue. Capt. Zaharie Ahmad Shah was a hero struggling with an impossible situation trying to get that plane to Langkawi.

While the fire theory now seems unlikely, the idea that something potentially uncontrollable went wrong has stuck.

The search area, some 120,000 square kilometers of the southern Indian Ocean off Western Australia, was designated based on the theory that the pilots were either unconscious or dead and that the flight was continuing on autopilot. That's the situation that would lead it to dive, not glide into the ocean for its final resting as Mr. Kennedy, the Dutch search team leader, referenced.

His questioning of that theory this week was echoed by Martin Dolan, chief of the Australian Transportation Safety Bureau, earlier this year. When commenting on the inability of the team to find the plane in the search area after two years, Mr. Dolan said:

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“The alternative is, frankly, that despite all the evidence, the possibility that someone was at the controls of that aircraft and gliding it… If we haven’t found it, then we’ll have to be contemplating…that there were control inputs into that aircraft at the end of its flight.”

The glide view is not supported by the investigating agencies, Reuters reports. Those agencies would presumably have had access to the confidential forensic report leaked by New York magazine, although some suggest that authorities have been reluctant to get behind a theory implicating the Malaysian captain.