CHARLESTON, S.C.  — Dylann Roof’s confession to killing nine black church members in a racially motivated attack last year will be publicly aired for the first time Friday when prosecutors play a recording of police questioning the young white man.

The recording may offer more insight into why Roof attacked the Emanuel African Methodist Episcopal church during Bible study on June 17, 2015. In an opening statement earlier this week, assistant U.S. Attorney Jay Richardson said Roof not only confessed, but gave chilling details on his preparation and his motivation for the attack when he spoke to law enforcement.

Roof is charged with 33 federal counts, including hate crimes. His defense has largely conceded that he committed the slayings and has instead focused on trying to spare him the death penalty. If jurors find him guilty, they will decide whether he should be put to death or spend the rest of his life in prison.

Prosecutors said Thursday that they planned to play the entire two-hour confession Roof gave shortly after his arrest the day after the shooting.

Roof has remained nearly quiet since. In court, his answers have almost always been a simple “yes” or “no.” The only other glimpse into his motivation was a 2,000-word statement he posted online on the afternoon of the shooting and 60 photos he carefully picked from more than 1,000 he had taken, Richardson said.

In Roof’s essay, he said he thought blacks were stupid, inferior to whites and violent. Among other things, he wrote, “we have no skinheads, no real KKK, no one doing anything but talking on the internet. Well someone has to have the bravery to take it to the real world, and I guess that has to be me.”

Roof’s lawyers have tried to spotlight his age at the time of the crimes — 21 — or that he didn’t resist when he was arrested.

On Thursday, jurors saw stark 360-degree photographs of the crime scene in the church’s fellowship hall. They saw the victims lying in pools of blood with bullets and ammunition magazines scattered around the scene.