A week ago, Dylann Roof is said to have bragged that he wanted to kill a bunch of people.

But the skinny 21-year-old high school dropout with a boyish bowl-style haircut -- and a menacing, dead-eyed scowl, at least in a photo on Facebook -- apparently has a dry wit.

So no one paid attention.

In the end, Roof -- middle name Storm -- seems to have been very, very serious.

The South Carolina man was to appear in court Friday, charged with nine counts of murder in a shooting rampage in an historic African American church in Charleston. Roof is white; the victims were all black.

Conflicting descriptions are emerging of the latest protagonist in a mass shooting in racially tense, gun-crazed America.

Roof was quiet and introverted -- a soft-spoken loner, one narrative says.

No, he was a bomb waiting to go off, bristling with hatred -- a calculating believer in racial segregation. Indeed, he wanted to kill blacks to stir up another war, says the opposing one.

An uncle of Roof, Carson Cowles, is quoted as saying Roof's paroxysm of violence at Emanuel African Methodist Episcopal Church came out of the blue.

Cowles said he got word to turn on the television Thursday when Roof was identified in surveillance footage from outside the church as the suspect in the shooting.

Roof allegedly sat in on a Bible study class for an hour before opening fire on the worshippers around him, and left some alive to tell about it afterwards.

"I watched it for 10 minutes, trying to convince myself this is just a nightmare, and I need to wake up," Cowles was quoted as saying in the Los Angeles Times.

"None of us saw it coming, but here we are, and there's no turning back," said Cowles.

But Roof himself told investigators he wanted to start a race war, one law enforcement official told CNN Friday.

'Flat out' warning of plan

Friends of Roof say he had in fact talked of killing -- and even said when and where.

Christon Scriven, who is black, says Roof warned last week that on Wednesday -- the exact day of the shooting, in the end -- he wanted to kill people at a local college.

"He flat out told us he was going to do this stuff," Scriven told the New York Daily News. "He's weird. You don't know when to take him seriously and when not to."

Only the location of the killing turned out to be different.

Roof's roommate at the trailer park where they lived in the city of Lexington -- outside the state capital Columbia -- said he had been planning something awful.

"He was big into segregation and other stuff," Dalton Tyler said.

"He said he wanted to start a civil war. He said he was going to do something like that and then kill himself."

But Joey Meek, a childhood friend of Roof, said he had black friends and was not in the habit of disparaging African Americans.

"He never said the n-word, he never made racial slurs, he never targeted a specific black person," Meek told ABC News. "He never did any of that, so it was just pretty much a shock."

But the time prior to Roof's alleged murder spree does suggest he was a troubled, biased person.

In a picture on his Facebook page, he is seen wearing a patch with the flag of apartheid-era South Africa and another of the flag of Rhodesia, the white-ruled country that eventually became Zimbabwe.

Roof dropped out of high school and was once arrested for possessing a drug used to treat addiction to opiates, news reports said.

His uncle was quoted as saying that in April, Roof got a .45 Glock gun from his father as a birthday present.

Two weeks ago, Roof went on a drunken rant about segregation and killing people, Meek said.

Meek took the gun away from Roof but gave it back the next day, he told the Daily News.

"I only took it away because he was drunk. I didn’t take him seriously," Meek said. "I do feel a little guilty because I could have let someone know."