A federal court found Dylann Roof guilty of killing nine people at the Emanuel African Methodist Episcopal Church in Charleston, South Carolina in June 2015.
The decision was arrived at by jury members who convicted Roof on all the 33 charges leveled against him.
A retired nurse and one of the few survivors of the shooting, Polly Sheppard, testified last in the trial. She said that Roof started firing when all the other members were praying with eyes closed at the end of the prayer. Suddenly, she heard the gun sounds but couldn't make out if those really were gun shots.
Then she heard another member Felicia Sanders, who is also alive, saying, "He's shooting everybody, Miss Polly!"
She hid under a table for cover and prayed aloud, but Roof told her, "Have I shot you yet?" Then Roof continued, "I'm not going to. I'm going to leave you here to tell the story."
In earlier testimonies, Roof said that he had had second thoughts about shooting and could have walked out of the church.
"I was sitting there thinking about whether I should do it or not. That's why I sat there for 15 minutes. I could have walked out," Roof said.
Church CCTV footage showed that Roof was inside for as many as 45 minutes.
He was asked if he wanted to kill more black people, to which he replied, "Oh no. I was worn out."
Two handwritten notes were found in Roof's car, one each to his mother and father, according to a crime scene technician.
To his mother, he had written: "As childish as it sounds, I wish I was in your arms."
"I love you and I am sorry. You were a good dad," he told his dad in the note.
Roof has admitted his crime in a videotaped interview, and had offered to plead guilty if prosecution would pardon him of death sentence. But, uncertainty over his sentence looms and he is awaiting his penalty which will be announced in January.
Statements about his state of mind and personal characteristics will not be heard till the penalty phase of the trial begins.