Early Sunday morning, police and FBI agents arrested two white men in connection with an early Friday shooting rampage that left three black people dead and two others wounded in a series of four attacks in Tulsa, Okla. Law enforcement officials accuse Jake England, 19, and Alvin Watts, 32, of carrying out the shooting spree in Tulsa's predominantly black north side, and on Monday, the pair appeared in court, with bond set at more than $9 million each. England's Facebook account offers a possible motive for the murders: Revenge for the shooting death of his father, Carl England, two years ago, allegedly by a black man. "It is way too early to call this a hate crime," FBI agent James Finch cautioned on Sunday, though some local officials are less hesitant. What happened in Tulsa, and what are the chances that race was the motive? Here's what you should know:

What exactly happened?
Around 1 a.m. on Friday, a gunman shot Dannaer Fields, 49, who later died in the hospital; three minutes later, two more black people were shot and wounded. Over the next two hours, Bobby Clark, 54, and William Allen, 31, were gunned down. All the victims were walking through the neighborhood, and some witnesses say men matching England and Watts' description stopped to ask directions, then shot the respondents in the back as they walked away. 

How did police catch England and Watts?
On Saturday, the Tulsa Police Department, Tulsa County Sheriff's Office, FBI, and U.S. Marshals Service formed a task force called Operation Random Shooter, then pleaded for clues from the community. One of the surviving victims said a white gunman was driving a white truck, and tipsters fingered England, saying he was trying to burn the truck. Police found a burned-out white pickup registered to England on Saturday night, obtained warrants, and arrested England and Watts around 2 a.m. Sunday in a trailer four miles from the house they shared, apparently as roommates. Police also found a gun they believe was used in the shooting, but didn't say which of the men is suspected of pulling the trigger. 

Why are people suggesting this was a hate crime?
In part because two white men allegedly shot five black people. "That fits the bill for me," says Tulsa's sole black councilman, Jack Henderson, suggesting that whoever did the shooting was "very upset with black people." There's also the Facebook message England posted at 4:04 p.m. on Thursday afternoon: "Today is two years that my dad has been gone shot by a f--king ni--er. It's hard not to go off between that and Sheran. I'm gone in the head." Carl England was shot dead on April 5, 2010; a black man named Pernell Demond Jefferson is serving a six-year term in connection with the fatality. Sheran Hart Wilde was England's 24-year-old girlfriend and the mother of his infant son. She committed suicide in January.

Does everyone agree that race was a factor?
No. England's supporters say race had no part in this, and that he is out of his mind over his father's death and Wilde's suicide. "His head is not on straight," a woman told CBS News, as she pulled up to England's house. "He needs help ... Jake is not a bad person. He is really not." The police are noncommittal on whether race was involved. "You could look at the facts of the case and come up with what would appear to be a logical theory," Tulsa Police Chief Chuck Gordon said Sunday, "but we're going to let the evidence take us where we want to go."

Sources: ABC News, AP, CBS News, CNN (2), Global GrindLos Angeles Times, Reuters, Tulsa World (2)