Other people then became involved and attempts were made to sell the stolen pages to a newspaper.
Mr Parfitt was arrested after the newspaper contacted the police.
His solicitor said that Mr Parfitt was "extremely embarrassed about the trouble he had caused".
He added that Mr Parfitt was likely to lose his job.
The magistrates are now considering how to punish Mr Parfitt and his sentence will be handed out on 4 June.
Three others - Garry Cox, 18, from Harleston in Norfolk and two 16-year-olds who cannot be named for legal reasons - have been charged with handling stolen goods.