Convicted paedophile and American national William Vahey, 64, taught at a string of schools around the world, after avoiding the sex offenders register in California.
Vahey was convicted over a child sex offence in California in 1969 but appears to have failed to sign the sexual offenders' register, which allowed him to slip through the net and go on to work in several schools.
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The Duke of Cambridge also laid a wreath to honour the victims before kick-off.
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