Because he doubts Flynn lied and wants to know what’s what and if he was forced into it.
On February 15, 2017 — that would be 16 months ago — Senate Judiciary Committee chairman Charles Grassley and ranking Democrat Dianne Feinstein asked the Justice Department to turn over the transcript of fired national security adviser Michael Flynn’s infamous call with the Russian ambassador, plus other documents related to the Flynn case.
The department refused.
Some of Grassley’s and Feinstein’s questions were answered the next month, on March 15, 2017, when the FBI’s then-director, James Comey, briefed the committee on Flynn and other matters in the Trump-Russia investigation. It was at that briefing that Comey told lawmakers the FBI agents who interviewed Flynn did not believe he lied to them.
“Then-director Comey led us to believe during that briefing…that the Justice Department was unlikely to prosecute [Flynn] for false statements made in that interview,” Grassley wrote later.