DUNCAN, Okla. -- It began as an afternoon jog in the steamy prairie heat.
Looking to shake off jet lag from a 41-hour odyssey that he and his American girlfriend had endured traveling back from his native Australia, Christopher Lane was chugging along Country Club Road here this summer when a black hatchback pulled up from behind. Someone fired a .22-caliber round into Mr. Lane's back, piercing his lungs, esophagus and two arteries. He died about an hour later.
By nightfall, the police had arrested three teenagers, one of whom told investigators that they had shot the runner because they were bored and looking for a thrill.
That chilling statement put Duncan, best known as the birthplace of the Halliburton Company, the energy services giant, at the center of an international storm. A former Australian deputy prime minister warned fellow citizens about visiting the United States, saying it was awash in guns. Commentators called it a hate crime and asked why the coldblooded killing of a white man had not attracted the same attention as the shooting of Trayvon Martin. Even a White House spokesman weighed in, saying, "There is an extra measure of evil in an act of violence that cuts a young life short."
A closer look at the shooting shows it was not about race. One of the three suspects was white, another had a white mother and a third had many white friends, including a girl he had been dating. "It was not a black-on-white crime," District Attorney Jason Hicks of Stephens County said.
It was instead a tale about teenagers from broken families, lives complicated by drugs and poverty, who seemed idle, alienated and drawn to a small-town version of urban gang culture.
"I see boredom all over town," said Jennifer Luna, the mother of one of the suspects, Chancey Luna. "He would say to me that there ain't nothing to do here. Nothing."
The evening of Mr. Lane's death, the police, acting on a tip, apprehended the teenagers in a church parking lot: James Edwards Jr., 15 at the time, Mr. Luna, 16, and Michael Jones, 17. Mr. Edwards and Mr. Luna have been charged as adults with first-degree murder. Mr. Jones has been charged with use of a vehicle in the discharge of a weapon and accessory after the fact to first-degree murder. He was charged as a youthful offender. All three could face up to life in prison.
Halliburton long ago relocated its headquarters, but the company still has a significant presence here and accounts for some 2,800 jobs in and around Duncan, according to the town's Chamber of Commerce and Industry. Duncan, located about 80 miles southwest of Oklahoma City, is a quiet town of more than 23,000 people that once called itself "The Buckle of the Oil Belt." Mr. Lane, 22, would stay in Duncan with his girlfriend's parents, who live in town and work for the company.
He had come to Oklahoma in 2009 as a baseball recruit -- he was a catcher -- to Redlands Community College in El Reno. His first season was lost to injury but redeemed when he met Sarah Harper, a member of the golf team.
"My transition to adulthood was shaped with him," Ms. Harper said. "He made me more open to the world."
In 2011, Ms. Harper left Redlands for Oklahoma Christian University in Edmond, and a year later, Mr. Lane transferred to East Central University in Ada. He was a business major. With a long drive between their campuses, the couple would meet at her parents' home in Duncan on weekends. Their spacious brick house is where Mr. Lane started his jog on Aug. 16.
There have been few homicides in Duncan in recent years. Poverty, however, is prevalent. And Elm Terrace Apartments, a privately run, low-income housing complex, is on the poor, east side of town.
That is where James Edwards's father is a maintenance man and where Mr. Edwards and the other suspects spent much of their idle time. None had regular jobs and many days were passed watching television, playing video games and smoking marijuana at Elm Terrace.
"Spending time at the apartments," Ms. Luna said in describing her son's summer, "and just running around."
Mr. Edwards's mother is in prison for a 2010 parole violation for fraudulently obtaining prescription painkillers. Relatives said that he was taunted about his mother and reacted by brawling, leading to school suspensions and run-ins with the police.
"There were students and adults who made nasty remarks about his mother and told him he would turn out to be no good," his half-sister, Rachel Padilla, 37, lamented.
Mr. Edwards, known as "Bug," was living with his father. But they would have disagreements, friends said, so he would also stay with friends, including Mr. Luna. He embraced his friend's mother as a surrogate parent.
"Bug called me 'Mom' and told me he loved me," Ms. Luna said. "Bug would cry and tell me his dad looked down on him and that he felt he was nothing to him."
But in recent months Ms. Luna noticed Mr. Edwards was becoming more hostile and withdrawn. One time, he threatened to shoot her oldest son. She soon told Mr. Edwards to move out.
He was an accomplished wrestler in school who dreamed of competing in the Olympics, wrote rap lyrics and recorded songs with friends at Elm Terrace. But aggression was a constant.
"Sometimes when he was angry or having a bad day, he would put on a 50-pound weight vest and jog to the Walmart a few miles away," his father, James Edwards Sr., said.
Last year, James Jr. was charged as a juvenile with assault and battery, the authorities said. He was also suspended from school for taking pictures of a student in the bathroom and posting them on Facebook, his father said. The suspension halted his wrestling aspirations, leaving him bitter. And early this year, Mr. Edwards said, his son and another boy were charged with larceny for stealing a cellphone.
Over the years, Mr. Luna, too, sought sanctuary outside his home. He called himself "Baby Drake," and bounced among relatives' homes.
"He was raised with God and went to church when we went, four times a week," his grandmother Dorothy Bumpas said. Mr. Jones went to the same Pentecostal church.
Mr. Luna, who also had a history of fighting, did poorly in school, dropped out and talked about joining the Army.
Last fall, his uncle and aunt, with whom Mr. Luna was living, made him leave for smoking marijuana. "There was a big blowup about it," said Robert Yates, a Duncan barber who is the brother-in-law of Mr. Luna's uncle.
His mother became so concerned he was using methamphetamine that she bought a drug testing kit. "It only came back positive for marijuana," she said.
Last December, two of Mr. Luna's relatives, including his 25-year-old half-brother, died unexpectedly, sinking Mr. Luna into depression, relatives said.
Michael Jones also did not have much of a relationship with his estranged parents, and spent time living with his grandparents, his grandfather Ronald Howard said.
Mr. Jones, known as "Tugboat," was a wrestler and a drummer who enjoyed fishing and had excelled in the Cub Scouts. But he failed in school and was left back at least twice, including last year. "He was so much older than his classmates, so it was thought best for him to study for his G.E.D. and not return to high school," Mr. Howard said. He planned to become an auto mechanic.
Last year, Mr. Jones's weight plummeted. Some friends and acquaintances feared he was abusing methamphetamine.
Around this time, Mr. Jones had stayed with friends, the Harris family, for about two weeks. "He was kind of homeless and was trying anything and everything to make money," recalled Chris Harris, 43, whose son had been friends with Mr. Jones since they were 10. That included stealing two window air-conditioners from a house next door, he said.
Mr. Jones's 16-year-old girlfriend was pregnant, and Mr. Harris told him that "he had to man up and not act like an idiot, and needed to get a job."
Just before the shooting, a law enforcement official said, the three suspects were driving in Mr. Jones's 2003 Ford Focus when they came upon Mr. Lane. Shortly after, they slipped behind a hotel for 11 minutes and smoked marijuana, the police say. Then they headed to the town courthouse, where Mr. Edwards had a meeting to sign a probation agreement from the larceny case.
Mr. Edwards stepped out of the car, calmly greeted his father, kissed a friend's baby on the head and walked inside.
Mr. Jones was the driver in the shooting, the police said. He told investigators that Mr. Luna was the gunman and that he was sitting in the back seat. Mr. Edwards was in the front passenger seat, according to the authorities.
Chief Dan Ford of the Duncan police said that officers believe that the three young men are linked to four suspects charged with several convenience store robberies in town earlier this year. (Both the police chief and the district attorney spoke before a gag order was issued in Mr. Lane's case in late August.) The police suspect that Mr. Edwards was a lookout in at least one.
Two weeks to the day after Michael Jones was arrested, his girlfriend gave birth to their son.
"We thought we knew Michael so well," said the girlfriend's mother, who spoke on condition of anonymity, citing privacy concerns. "He seemed like nothing more than a regular kid."
Sheelagh McNeill contributed research from New York, and Kitty Bennett from Seattle.
Correction: October 1, 2013, Tuesday
This article has been revised to reflect the following correction: Because of an editing error, an earlier version of this article misidentified the former Australian official who warned fellow citizens about visiting the United States. He was a deputy prime minister, not prime minister.
This article originally appeared in The New York Times.