Lane played at East Central University in Ada, 85 miles east of Duncan, and had been visiting Harper and her parents after he and his girlfriend returned to the U.S. from Australia about a week ago.
His old team, Essendon, scheduled a memorial game for Sunday to raise funds for Lane's parents as they worked to have their boy's remains sent home.
At Essendon Catholic School, Lane will be remembered at a November Mass in which all former students who have died are mourned and celebrated, former school captain David Ireland told The Age newspaper in Melbourne.
"He was the sort of guy at school who everyone knew and knew quite well," Ireland said of Lane. "He loved his footy (Australian football) and his sport and spent a lot of time with mates."
Melbourne's Herald Sun newspaper reported that roses and a baseball were placed Monday on the home plate where Lane played as a youth with the message, "A wonderful young man taken too soon. Why?"
Former deputy prime minister Tim Fischer criticized the National Rifle Association and asked Australians to avoid the U.S. as a way to force its Congress to act on gun control.
"Tourists thinking of going to the USA should think twice," Fischer told the Herald Sun. "This is the bitter harvest and legacy of the policies of the NRA that even blocked background checks for people buying guns at gunshows. People should take this into account before going to the United States. I am deeply angry about this because of the callous attitude of the three teenagers (but) it's a sign of the proliferation of guns on the ground in the USA. There is a gun for almost every American."
Tara Harper, Sarah Harper's cousin, said her family was working with the Lanes on funeral arrangements but that the girlfriend didn't want to attend court proceedings.
"She wants nothing to do with them. She doesn't want to see them. She doesn't want to hear them," Tara Harper said. "I don't think we'll ever know why it happened. No answer will ever be satisfying, no matter what it is."
Police said they had been called to a home in Duncan's gritty east side in response to a possible shooting. At the home Tuesday, pieces of cement with the phrases "happiness lives in hearts that love" and "with God all things are possible" written on them sat cracked on the front porch.
One window was covered with foil, and cardboard and a satellite dish was perched on the roof. No one answered at the home or at homes next door or across the street.
At the site of the shooting, Bill Renfrow, 85, said he saw emergency workers tending to Lane and believed there had been a hit-and-run accident behind his home.
"It's very saddening. It's a terrible thing to happen. It's so unusual," he said, later adding: "He was a guest in the country."