Stansted Hijacker working at Heathrow Airport

We all expect the people working at Airports to have no criminal records since they are given accesses to various restricted areas of the airport. So, how can a country that claims (and should) have such high security standards allow a person responsible for hijacking a plane some 8 years ago to work at their main airport?

From AFP -

“Nazamuddin Mohammidy, 34, was among nine Afghans who threatened to
blow up a Boeing 727 during a four-day stand-off with police at London
Stansted Airport in 2000.

This week he appeared in court after
police pulled his car over, on suspicion of being a bogus taxi driver,
only to discover his identity and that he had a security pass as a
cleaner for British Airways, said The Sun newspaper.”

From here -

“
There was a four-day stand-off before the gang, who claimed they faced Taliban persecution, gave themselves up.

They were jailed for their part in the hijack, but those convictions were later quashed by the Court of Appeal.“