Lawyers representing Christine Blasey Ford, the California professor who alleges Supreme Court nominee Brett Kavanaugh sexually assaulted her when they were teenagers in high school, want the FBI to conduct an investigation before she agrees to testify. The attorneys—Debra Katz and Lisa Banks of the Washington firm Katz, Marshall & Banks—made their request in a letter Tuesday night to Senate judiciary leaders.

“As the Judiciary Committee has recognized and done before, an FBI investigation of the incident should be the first step in addressing her allegations,” Ford’s attorneys wrote. “A full investigation by law enforcement officials will ensure that the crucial facts and witnesses in this matter are assessed in a non-partisan manner, and that the Committee is fully informed before conducting any hearing or making any decisions.”