Hillary Rodham Clinton has hired veteran Democratic campaign lawyer and organizer Charlie Baker for a senior administrative job in Clinton’s 2016 campaign, a campaign official and others said Tuesday.

Baker, now a senior adviser with the Democratic strategy firm Dewey Square Group, will be the campaign’s chief administrative officer. He is already working with the three-week-old campaign on an informal basis and will take up the formal role in about a month, people familiar with the plan said. Baker’s role was intended to be kept under wraps for several more weeks, and neither the campaign nor others familiar with the hire would speak for the record.

Once he fully joins the campaign headquarters in Brooklyn, N.Y., Baker is expected to play a senior role overseeing campaign interactions with the Democratic Party, including the party committees and 2016 Democratic National Convention plans. The campaign official who confirmed Baker’s hiring would not confirm those duties.

Baker has extensive campaign experience, particularly in field operations and get-out-the-vote operations. He served on board of the Super PAC Priorities USA during the 2012 election, in which the group raised millions for President Obama’s re-election. Baker has since resigned from the group, now known as Priorities USA Action, and which is now supporting Clinton’s presidential bid.