[Crowcreek]

Semtex or C-4 would have left chemical traces on the wreckage. It should be an easy matter to rule it out -- or confirm it.

[MsLady]

I know nothing about explosives, is the residue visible? Or do they have to run a test?

[null and void]

Semtex or C-4 would have left chemical traces on the wreckage. It should be an easy matter to rule it out -- or confirm it.

IF that's what they really want to do...