As Chief Judge Alex Kozinski called for an investigation Thursday into the sexually explicit images he kept online, just how he could be disciplined becomes a key question.

Normally, each circuit’s chief judge screens complaints against federal judges. But since Kozinski himself is the chief judge, that task now falls to the active judge with the most seniority. In this case, the individual Kozinski just replaced as chief — Judge Mary Schroeder — would handle the proceeding, said University of Pittsburgh School of Law professor Arthur Hellman.