After four days of intense questioning of potential jurors in the perjury trial of former star pitcher Roger Clemens, the pool was narrowed Thursday to the magic number: thirty-six.

Prosecutors and defense lawyers will now have the chance to further winnow the field to 12 jurors and four alternates.

Opening statements are expected to begin Monday in the District’s federal courthouse in the high-stakes trial, which may last as long as six weeks.

Clemens is accused of lying to Congress when he denied using performance-enhancing drugs.

He is on trial for a second time, after his first case was cut short last summer because of an error by government lawyers.

Read more: Clemens trial coverage