My neighbor's bright college student son, "Tony," who is into spy novels, mysteries and non-fiction books about espionage, speculates that this suspicious crash was a cover-up for an assassination -- someone was onboard that the "black hats" wanted dead, and they were willing to kill an entire aircraft full of people to accomplish their goal. He says that the passenger list will be carefully scrutinized by intelligence agencies to see if any likely target for such a murder can be identified.

The method "Tony" suspects was used to incapacitate all the passengers and crew without a depressurization alarm or other visible damage was release of a toxin in the form of a rapid-acting, highly dispersable gas or chemical agent. That could account for the O2 masks observed by the fighter pilots, which would have been deliberately deployed and were likely functional when people began to go down, but wouldn't help once the toxin had been inhaled/absorbed. Tony says that sabotaged electronics would have been timed to simultaneously disable radio communications with the ground to prevent a report from being made.

I'd like to dismiss "Tony's" speculations as just the product of an over-active imagination at work in a brain not yet fully matured. But I remain disquieted about the scenario he proposes. Is there a toxin that could be deployed as he described? If there is, would it be detectable somehow after the crash?