President Donald Trump asked then-FBI Director James Comey to back off the investigation of former National Security Adviser Michael Flynn shortly after Mr. Flynn had resigned, according to two people close to Mr. Comey.

The people said they had seen a memo written by Mr. Comey that documented a meeting with the president during which Mr. Trump told the director that he hoped he could find a way to drop the Federal Bureau of Investigation’s probe of Mr. Flynn.

...