I forgot about 9-11, that does look fishy.
The other new information is that there was no battery and he had that thing plugged during the class.
If it is true then I don't know, I am not so sure it was not a hoax of some kind.
Setting up alarm in the class with it plugged would be hard and very deliberate.
Clocks usually can run for a few minutes without any external power including backup battery. So it was possible he for some reason took battery off and plugged it into AC, but that would make no sense.
Also I assumed he said he was trying to impress his engineering teacher, not english one.
Anyway, I agree with that dude, it all looks fishy, they kid who was called a bomb-maker in school, brings a fake-bomb looking device right after 9-11.
Looks like Richard Dawkins is getting in on it too:
http://www.theguardian.com/science/2015/sep/20/richard-dawkins-questions-ahmed-mohamed-motive-backlash
In a tweet, the scientist linked to a YouTube video entitled Ahmed Mohammed [sic] Clock is a FRAUD, in which user Thomas Talbot alleges Mohamed’s clock “is in fact not an invention. The ‘clock’ is a commercial bedside alarm clock removed from its casing”.
In his tweet, Dawkins said: “If this is true, what was his motive? Whether or not he wanted the police to arrest him, they shouldn’t have done so.” His next tweet said of the video: “This man seems to know what he’s talking about.”
Hey, Dawkins agreed with me