Call For An Investigation?

What does this mean?:

The criminal prosecution of a hard-core pornographer turned into a personal trial for the presiding judge, who called for an investigation Thursday into his own conduct over lewd photos and videos stored on his family's publicly accessible Web site.

No, an explanation is called for, not an investigation. If he doesn't know what he himself is doing, there's no point in convening a panel to investigate the matter. The panel would have to take the judge's testimony second-hand anyway.