Atkinson said that "Gray presented Mr. Thompson with a 1-page budget for $425,000. He asked Mr. Thompson to pay for a get-out-the-vote campaign. Mr. Thompson agreed."
The charges against Thompson come as Gray seeks re-election against seven challengers in the April 1 Democratic primary.
Gray has not been charged with a crime and has denied any wrongdoing in the 2010 campaign.
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.