Roger Stone was the linchpin of a months-long effort by Donald Trump’s 2016 presidential campaign to discover damaging information on Hillary Clinton to be released by the anti-secrecy group WikiLeaks, an effort that began before the hack of Democratic emails was publicly known, Stone’s trial has shown.The trial in federal court in Washington turns on accusations that Stone lied to Congress about his attempts to learn more about what WikiLeaks would publish and when it would do so. But some testimony also raises questions about the president’s written assertions under oath that he did not recall being aware of communications between Stone and WikiLeaks or recall any conversations about WikiLeaks between Stone and members of his campaign.