Irrespective of whether your crime counts as 'moral turpitude', you're
meant to apply for a visa if you've ever been arrested (even if totally innocent) or convicted of any offence. That's according to the website of the US embassy:
http://london.usembassy.gov/cons_new/visa/niv/ add_crime.html
In particular, the website states:
"Applicants who have been arrested and/or convicted of a drink related offense may be referred to the Embassy's panel physician for evaluation".
However, the US authorities have no direct access to UK criminal records (including fingerprints). European law prohibits the government of any EU country from making personal data (including criminal records) available to foreign powers unless there is 'justifiable cause'. (i.e. the UK can pass on information about suspected terrorists, drug traffickers and sex tourists but it can't generally open up criminal records to other countries).
Even if the USA has finger print and retinal scanners, they still won't know about your conviction.
Chris