CHARLESTON, S.C. — Dylann S. Roof, a self-radicalized young white supremacist who killed nine black parishioners last year when he opened fire during a long-planned assault on Emanuel African Methodist Episcopal Church, was found guilty by a federal jury here on Thursday.

Mr. Roof, 22, stood, his hands at his side and his face emotionless, as a clerk read the verdict aloud in Federal District Court, where he had been charged with 33 counts, including hate crimes resulting in death.

Mr. Roof, whose lawyers conceded his guilt, will face the same jurors when they gather on Jan. 3 to begin a more suspenseful phase of his trial to decide whether he will be sentenced to death or life in prison without parole.

The jury deliberated for only about two hours on Thursday afternoon, and as a clerk began to read the guilty verdicts, one after the next, a few women in the courtroom nodded with satisfaction. After the court adjourned, the two adult survivors of the attack, Felicia Sanders and Polly Sheppard, shared a long embrace.