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."
Security camera, call to police aided investigation
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.
A chart in 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.