Malaysia Airlines Flight MH17: Crash cause coverup likely impossible

Since pro-Russian separatist rebels took control of theMalaysia Airlines Flight MH17crash site, concerns have been raised that the insurgentsaccused of downing the jetlinermay have tampered with or hauled away debris.

Although the site may have been compromised, experts saythere will likely be enough evidence and cluesscattered about to get answers aboutthecrash, even if the rebels have attempted to hide the cause.

I never say never about anything, but I kind of doubt they could identify and find all the pieces, said Richard Marquise, a former FBI agent who led the task force investigating the bombing of Pan Am Flight 103 over Lockerbie, Scotland. I mean, if they sent a team of 1,000 people there, let's presuppose it was the Russians they might be lucky to pick up every single piece and walk away with it, but I think in a huge crime scene its very difficult.

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So far, separatists have given international observers only limited access to the crash site. On Monday, U.S. President Barack Obama accused the separatists of impeding the investigation and removing evidence.What exactly are they trying to hide? he asked.

In the case of the bombing of Pan Am Flight 103, forensic specialists found framing from an aluminum baggage container marred with the residue of high explosives. Thisallowed investigators to determine quickly that a bomb had brought down the plane, Marquise said.

Fragments from the fuselage also revealed thatthe blast did not come from outside the aircraft. Meanwhile, investigators found on the ground atiny fragment no bigger than a thumbnail that came from a radio/cassette player that had been used to store the bomb, and afragment from a timer that could be traced to Libya.

UnlikeLockerbiebombing case

Thecase of Flight MH17 is different, if it was a missile that brought down the Boeing 777. Wreckageof the plane, which might be scattered over kilometres,would be important to determine whether the plane was downed by an external force.

"If it was an explosive device, what the investigators would be looking for is evidence of that explosive device, said Phil Giles, who worked in Britain's Air Accidents Investigation Branch and was part of the Lockerbie bombing investigation team "Thats all stuff that, with people poring over the site, can get trampled on, moved. Whereas with this [crash] youre really in a different scenario.

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Once you found some evidence like big holes in the side of an airplane, which indicates a rocket has gone off near it,youre not that interested in finding the timing mechanism of the rocket.

Forensic investigators will try to locate the outside skin of the airplane and see if they can prove that something went into the fuselage.If the missile didnt directly hit, but detonated at a point near the fuselage up next to the lower end of the cockpit, investigators should still find metal deformed inward, said Billie Vincent, former head of securityforthe Federal Aviation Administration. As well, anything exploding near a metal object is going to leave minute particles from the explosive.

Difficult to conceal missile fragments

If it was a missile, obviously finding those fragments is key. Giles said many ofthose fragments maynot end up in the same place as the aircraft.Butthere could be bits and pieces embedded in parts of the wreckage and in some of the dead passengers, making it unlikely anyone could walk away with all the evidence.

If its a missile, I dont think they will have done enough to actually conceal that fact, because its going to be so damaged and theres going to be so much evidence of the damage from the shrapnel going through the airplane, Giles said.

Once those missile fragments areidentified, they would begiven to experts in missile technology and forensics to try to figure out the make, and possibly, trace its history.

"I've seen these things for decades, where somebody can go back and trace who ordered these things, who were these made for, who was the customer,"Marquise said."Ithinkthey have a pretty good chance of figuring outthese weremade for thisgovernment, by this company and sold on this date. I think there's an awful lot of things,if they find some fragments of what we all think is probably a missile."

However, Vincent said, if the separatists are smart enough and grab the right pieces of the airplane, where the missile impacted or detonation occurred, they could still stymie the investigation.

"The question on this point will probably depend on the sophistication of the peoplethey have out, those rebels, and the level of expertisethe Russians bring in to try and find those things and confuse the environment."

ButMarquise said he remains "cautiously optimistic" that if realinvestigators get to the site in the next couple of weeks, they will be able tofind something that will "at least tie back to some group, country,whatever, wherethe world can make a political and diplomaticcasethat this is the government that is responsible."