Grassley's office referred Kavanaugh accuser to DOJ for making false statements.

Judy Munro-Leighton alleged that Justice Kavanaugh and a friend had raped her ‘several times each’ in the backseat of a car. 

The accusations were made via a "Jane Doe" letter provided to Sen. Kamala Harris, a California Democrat and committee member. 

Given her relatively unique name, Committee investigators were able to use open-source research to locate Ms. Munro-Leighton and determine that she: (1) is a left-wing activist; (2) is decades older than Judge Kavanaugh; and (3) lives in neither the Washington DC area nor California, but in Kentucky.  

Under questioning by Committee investigators, Ms. Munro-Leighton admitted, contrary to her prior claims, that she had not been sexually assaulted by ... Kavanaugh and was not the author of the original 'Jane Doe’ letter.

More juicy details at Fox News.

Even more granular details at Conservative Treehouse. Including Grassley's letter to FBI and DOJ.