How do judges normally treat destruction of evidence? Do they not care who committed the crime and just make a ruling on how to infer it? I feel like the court would want to know who has committed something as serious as this but I'm not sure of the actual process for it.
Don't worry about it. He'll totally deal with it outside his formal judicial capacity, after letting them off with a slap on the wrist... "in his own time" like some Hollywood renegade judge!
Under Federal Rules of Civil Procedure Rule 37 possible sanctions are as follows:
dismissal of the wrongdoer’s claim;
entering judgment against the wrongdoer;
exluding expert testimony; and
application of adverse inference rule.
The last of these basically allows the court to infer (or instruct the jury to infer) that the destroyed evidence was the most possibly damning thing and hold that against the party in question.
Outside of the above, destruction of evidence is a crime. The judge has no power of investigation that I'm aware of, but maybe it just means informing those who have such power.
All bark, no bite on the hand that will feed him after he leaves the bench (Big Capital/Big Law). See:
"And yet, the judge decided today that he would not issue a “mandatory inference instruction” — one that would tell the jury they should proceed with the understanding that Google destroyed evidence that could have been detrimental to its case.”