Judge Phillip Lester happens to be defendant Aaron Tanner's brother-in-law in the upcoming Tanner v. New Jersey trial. Keeping in mind the laws and regulations of the US court, Judge Lester must ___ from the trial.

Step down

Explanation:

In this scenario where the judge is the the brother-in-law of Aaron Tanner a party to an upcoming case, the judge will be required to step down from the trial based on the code of conduct for United States judges.

A judge is disqualified from a case when a judge's impartiality can be reasonably questioned.

One ground for disqualification is when the spouse of the judge or a person related to either one of them to the third degree is party of proceedings of an upcoming case.

A judicial bias is created in cases where the judge is related to a party because he will tend to favour the party he has had a relationship with.