Story highlights Edwards' sister says it's hard to believe he would kill someone

Three teenagers are charged in the killing of an Australian student jogging in Oklahoma

Rev. Jackson issues a statement calling for an end to violence

Ex-Australian deputy PM: People planning travel to U.S. "should think carefully about it"

One of the Oklahoma teenagers accused of killing 23-year-old Australian baseball player Christopher Lane previously posted images online showing himself posing with guns and wads of cash.

And three days before what police call the indiscriminate shooting , the suspect, 15-year-old James Edwards Jr., tweeted, "With my n****s when it's time to start taken life's" -- a line from the Chief Keef rap song, "I Don't Like."

Back in April, he tweeted, "90% of white ppl (people) are nasty. #HATE THEM."

Police in the town of Duncan have charged Edwards and Chancey Luna, 16, as adults with first degree felony murder, said Kaylee Chandler, a Stephens County court clerk.

Michael Jones, their alleged 17-year-old driver, faces two charges: use of a vehicle in the discharge of a weapon and accessory after the fact to murder in the first degree.

A judge set bond at $1 million for Jones and no bond for Edwards and Luna, Chandler said.

Police say it was Jones who ultimately told them, "We were bored and didn't have anything to do, so we decided to kill somebody."

The police affidavit lists Edwards and Chancey as black, and Jones as white.

Edwards' older sister said Thursday she finds it hard to believe her brother would ever post online messages about killing and hate.

"I know that he has a lot of Caucasian friends with whom he hangs with," Rachel Padilla told CNN's "Erin Burnett OutFront" from her home in Duncan. "The only way that I would feel that he would say anything racist about anybody is because that we have felt racism from some of the people here in the community of Stephens County."

Padilla said her brother has been in trouble with the police before for fighting, but she said he's never been a vicious person and she would never have thought he could kill someone. She said Edwards "hung around older people that were affiliated with gangs" but she doesn't know if he was in a gang himself.

Case triggers political, racial questions

The seemingly senseless killing has left many Americans disgusted. And for some, it triggered a political question with racial overtones in the wake of the polarizing Trayvon Martin case, in which an unarmed black teen was killed by a neighborhood watch volunteer who claimed self-defense. The acquittal of George Zimmerman, who describes himself as Hispanic, infuriated many people and triggered protests around the country, as well as remarks from President Barack Obama.

Now, some Americans are asking why this killing, in which the victim was white and the alleged killers black, has not brought reaction from the president.

The conservative news website townhall.com complained Wednesday that the Rev. Al Sharpton, a prominent civil rights figure, and the president, "who quickly opined on the George Zimmerman self-defense case against Trayvon Martin, are silent. Not only should they be publicly condemning the alleged killing, which is now an international incident, but they should be asking why the hell these teenagers were 'bored' in the middle of the day. Where were their parents? Where is Sharpton when it comes to condemning young black men joining gangs, as these three did?"

At the White House, spokesman Josh Earnest said Wednesday he was not familiar with the case. When asked why the president had not weighed in on it, he noted that when Obama spoke of the Trayvon Martin case, he also spoke in general terms "about the impact of violence in communities all across the country."

A look at Sharpton's Twitter feed and transcript from his August 21 program did not show any mention of Lane's death.

Thursday, the Rev. Jesse Jackson, another well-known civil rights figure, and his Rainbow PUSH Coalition issued a statement referring to both the killing of Christopher Lane and the recent beating of a white 13-year-old boy by three black teenagers on a school bus in Florida

The incidents call "each of us to a (sic) collectively resist all forms of violence in our society," he wrote.

"In particular black on black violence that disproportionately affects every facet of black life in America. These horrific episodes that leave all rationally thinking people appalled and others feeling paralyzed cannot be addressed by our silence and or abdicating our personal responsibility. We urge all persons who believe as we do in the (Martin Luther) King principle of peace all over the globe to rise to the challenge to pursue and promote peace and its principles. We must learn to live together in peace or we will most assuredly die apart in our own neglect."

911 call: 'If you don't hurry, he's gone'

Lane was a promising young athlete, living his dream of studying in the United States on a baseball scholarship.

The people of Duncan, an affluent town of fewer than 25,000 people, welcomed him.

Lane had gone out for a jog just at the time the teens had decided to find someone to kill, police say.

They drove their car behind him and opened fire, hitting him once in the back, authorities say.

He staggered across the road and fell to his knees, then managed to get up and take a few more steps before collapsing for good.

A woman who saw him struggling called 911. As she waited for an ambulance, the young man started to turn blue.

"If you don't hurry, he's gone," the woman warned.

The paramedics who arrived couldn't save Lane, and he was pronounced dead at a hospital.

He was "the most amazing person I've ever met," his girlfriend, Sarah Harper, told CNN's "AC360" on Wednesday. "He was the most genuine and kind-hearted guy and would do anything for anybody at any time and ... made everyone feel special."

"There is no way to describe what happened," she said. "It's the hardest thing you could ever imagine happening. ...There is still a lot of shock and disbelief, and a lot of anger and sadness."

"You can't make sense of it," she added. "It's just -- so surreal that anybody could do something like this."

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Immediately after the shooting, witnesses gave police a general description of a black car. Security footage from a nearby Mexican restaurant showed what could have been the car. But hours passed with no sign of whether there would be another killing.

Then, four hours after the shooting, a man called police, saying he could see three juveniles with guns -- and they apparently want to kill someone, said Duncan police Chief Danny Ford.

Officers responded to a home and found the car in a church parking lot across the street from the caller's house. The suspects were inside, and they provided enough information to be arrested.

Two days later, Edwards offered details about the case, police said. The teens had been inside a house when Lane ran by, and the group decided he'd be the target -- as a way to cure their boredom, Ford says.

Call for U.S. tourism boycott

The case has triggered fury among many people in Australia.

"It is another example of murder mayhem on Main Street," former Australian Deputy Prime Minister Tim Fischer told CNN's Piers Morgan.

chart i n the Washington Post, using data from The Organization for Economic Cooperation and Development, shows Australia to have among the lowest gun-related killings in the developed world. The United States had the highest. Former Prime Minister John Howard told CNN's Christiane Amanpour in March that gun control laws instituted after a mass shooting were responsible for the low number.

One Australian newspaper, under mug shots of the three suspects, ran the headline: "Faces of Evil: The teens American police say shot our star."

A Facebook page set up in Lane's honor, R.I.P Christopher Lane , had more than 67,000 followers by Thursday morning, with posts describing his slaying as senseless and tragic.

Lane grew up in Oak Park, a northern suburb of Melbourne in the southern state of Victoria. He showed sporting talent early on and started playing T-ball, a children's version of baseball, at age 7, according to Essendon Baseball Club president Tony Cornish.

"It's shocked our world. The baseball community in Australia is a tight-knit group. Most baseballers know most baseballers, and everyone's shattered," he said.

Cornish said Lane was a "very good athlete" who could have played Australian Rules football but chose baseball because it offered him the chance of a college education in America.

"If it didn't work out, he could have come back to Australia with an education and also been a much better baseballer. He would have been an elite player in Australia and at our club. That's the type of kid he is -- he created a 'win-win,' in a way, for himself," he said.

Harper said Lane loved to travel and loved the competitiveness of baseball.

Memorial game in Lane's honor

Lane's friends and family are being invited to a memorial game in his honor Sunday, and a donation page has been set up to raise money for a memorial fund in his name.

Harper visited the scene of Lane's death Tuesday. It's a grassy curb on a suburban street where flowers have been placed with messages of regret and condolence.

"I'm going to miss him forever. But I'm really glad that I got the four years with him," Harper told reporters. She and her family will travel to Melbourne for Lane's funeral on a date still to be set.

Lane's distraught father, Peter, told the media: "He's left his mark as we know, and you know there's not going to be any good come out of this, because it was just so senseless."

A former student and classmate at East Central University where Lane was studying described him as "a charming guy, genuinely good person, with great character and had a love for life."

"As cliched as it sounds, Chris was the kind of guy you want your sons to grow up to be and that you want your daughters to marry. It just breaks my heart knowing how much more he could have brought to this world as a husband, father, son, brother and friend," Sam Malchar said.

The shooting took place one day before the three suspects were due to return to school.

Security was tightened around the Duncan School District after anonymous phone threats were made to Duncan High School.

Schools opened as normal Wednesday, but students were not allowed to leave for lunch and parents were being told they could keep their children at home if they wished.