Question about Travel to U.S. on Visa Waiver Programme

[ramjet]

I know that in order to travel to the U.S. without a visa, you need to be eligable for the Visa Waiver Programme, even if you are only going on holiday as a tourist. For this purpose you have to fill in a form on the plane. If you have been arrested or convicted for any offence you are not eligable for the VWP and have to apply for a visa, which involves going to the US embassy in London, where you might be refused a visa in any event.

My question is: do the UK and the US share information about criminal records at present? If, hypothetically speaking, you were travelling from the UK to the US and you lied on the VWP form, how likely would it be that the U.S. customs officials could find out about your criminal record and have you deported? Is it easier for them to find out about certain offences? Obviously I would never do such a thing, but I am interested in how much information is shared between the two countries and how easy it would be for U.S. officials to obtain information about criminal records in the U.K.