New York State Attorney General Barbara Underwood’s office may move forward with its plan to depose a key U.S. Department of Justice official in its lawsuit over the citizenship question on the 2020 U.S. Census, the U.S. Second Circuit Court of Appeals decided late Tuesday.

Testimony from acting assistant attorney general for the Civil Rights Department John Gore could be an important step for investigators to figure out who was behind the citizenship question. He allegedly ghostwrote a letter from the Department of Justice to Commerce Secretary Wilbur Ross last year asking that the question be added.