WASHINGTON (CNN) -- The arduous process of jury selection in the criminal trial of a former top aide to Vice President Dick Cheney was finally completed Monday.

Opening statements are expected Tuesday in the trial of Lewis "Scooter" Libby, who is charged with perjury and obstruction of the investigation into the disclosure in 2003 of the identity of CIA officer Valerie Plame.

In three days of interviews last week, U.S. District Judge Reggie Walton and the trial attorneys rejected 19 potential jurors, many after they expressed negative views about the Bush administration.

However, it took only an hour and a half Monday morning to qualify a final six needed for the 36-person jury pool and less than that in the afternoon to whittle the pool down to 12 jurors and four alternates.

"We now have selected the jury that will hear the case," Walton said shortly before 4:45 p.m.

Libby resigned as Cheney's chief of staff after his October 2005 indictment by a federal grand jury probing the Plame disclosure.

-- CNN's Paul Courson