CHARLESTON, S.C. - A small group of parishioners was allowed inside the bullet-scarred Emanuel African Methodist Episcopal church on Saturday, getting a firsthand glimpse of the room where nine people from their congregation were slain.

Meanwhile, the FBI said it was investigating a manifesto purportedly written by the suspected gunman, 21-year-old Dylann Roof.

The website linked to Roof contained photos of him holding a burning American flag and standing on one. In other images, he was holding a Confederate flag, considered a divisive symbol by civil rights leaders and others.

The hate-filled 2,500-word essay talks about white supremacy and the author says "the event that truly awakened me was the Trayvon Martin case" - the unarmed black teenager fatally shot by neighborhood watch volunteer George Zimmerman while walking home in Florida in 2012.

The manifesto said "it was obvious that Zimmerman was in the right" and that the case led him to search "black on White crime" on the Internet.

"I have never been the same since that day," it said.

It's unclear whether Roof wrote the rants, but they are in line with what he has told friends and what he said before allegedly opening fire inside the Emanuel African Methodist Episcopal church Wednesday night.

Cleaning crews worked at the church Saturday, and church members announced they will hold a Sunday service. Harold Washington, 75, was with the small group that saw the lower-level room where the victims were shot.

"They did a good job cleaning it up," he said. "There were a few bullet holes around, but what they did, they cut them out so you don't see the actual holes."

He said he expected an emotional service with a large turnout today.

"We're gonna have people come by that we've never seen before and will probably never see again, and that's OK," he said. "It's a church of the Lord - you don't turn nobody down."

The church had that same welcoming nature when Roof walked into their Bible study, Felecia Sanders said at Roof's bail hearing Friday. Sanders survived the shooting, but her son Tywanza died.

As for the possible manifesto, Internet registry records show that the website was created Feb. 9 via a Russian registry service with the owner's personal details hidden. A man who answered the phone at the Moscow-based company would not say who the site's owner was.

Roof is being held in jail, facing nine counts of murder and a weapons charge.

A police affidavit released Friday accused Roof of shooting all nine multiple times and making a "racially inflammatory statement" as he stood over an unidentified survivor.

Roof had complained while getting drunk on vodka recently that "blacks were taking over the world" and that "someone needed to do something about it for the white race," according to Joey Meek, who tipped off the FBI when he saw his friend on surveillance images.

In Charleston, the grief was so palpable three days after the shooting that a family re-routed its trip home from the beach and a bride-to-be interrupted her wedding day to pay their respects.

"It's been a weird feeling, trying to have a celebration this weekend. But the whole city has been so supportive and such a show of grace," said Kathryn Cole, 27, who lives two blocks away from the church and is set to say her nuptials Saturday night. "Life is carrying on. We aren't letting this change our everyday lives."

Greenville residents Stacey and Kenneth Penland arrived in Charleston for vacation Friday. During their first full day in the city, they came to the church with their children, 6-year-old Luke and 3-year-old Logan.

"We've been at the beach, and then the market, and of course we stopped by here," said Kenneth Penland.

Derrick Jones was vacationing on Hilton Head Island when he decided to drive an hour out of his way home to Greenville. He stopped at the church with his wife and three boys.

"They've been asking questions all day since this has happened," Jones said. "And I don't really have all the answers. I try to explain it the best way I can."