When William Mott was 22, he was convicted of driving under the influence for an accident that killed a friend. Last June, Mott picked up his fourth DUI. His 9-year-old son was with him, so Mott also faced a charge of endangering a child. Mott sought treatment and says he’s overcoming his problems. Judge Kaufman set up a sentence he thinks will show if Mott is serious about changing.