Why did they swab my bag at the airport?

Why did they swab my bag at the airport? When swabbing is conducted, they are primarily looking for explosives or components thereof of course, but they can also detect narcotics. I once produced a positive as a result of having travelled in a car where the airbags had deployed during a shunt (they’re fired by a small explosive cartridge).

When swabbing is conducted, they are primarily looking for explosives or components thereof of course, but they can also detect narcotics. I once produced a positive as a result of having travelled in a car where the airbags had deployed during a shunt (they’re fired by a small explosive cartridge).