The state medical examiner's report said the fatal shot was fired at close range from a .22-caliber revolver into Lane's back at the level of his chest and heart.
Authorities have said three teenagers targeted Lane at random on Aug. 16 because they were bored, shooting him from a car in broad daylight as they approached him on an empty road. He died later at the scene as a passing motorist who had spotted him staggering about called 911.
Arrested four hours afterward were James Edwards Jr., 15; Chancey Luna, 16, and Michael Dewayne Jones, 17. Edwards and Luna were charged with first-degree murder, and Jones, driver of the car, with use of a vehicle in the discharge of a firearm and accessory to murder after the fact.
The nature of the murder -- Jones told police Lane was shot "for the fun of it" -- created widespread publicity of the case in the U.S., Australia and elsewhere. Lane, a native of Melbourne, was in Duncan to visit with his girlfriend and her family before returning for his senior year at Eastern Central University in Ada, Okla., which he attended on a baseball scholarship.
Because of the notoriety, a local judge Tuesday issued a gag order prohibiting attorneys, law enforcement officers and other officials connected with the case from commenting publicly about it. The judge said he did so in the interest of preserving both the prosecution and the defense right to a fair trial.
The gag order did not extend to the news media.
Meanwhile, in Essedon, Australia, a funeral and graveside burial services were held for Lane on Wednesday.
Australian media outlets reported that hundreds of the young athlete's family, friends and acquaintances attended. Prominent among them was girlfriend Sarah Harper, whose family home he was staying at in Duncan at the time of his death.
Details for this story were provided by the Duncan, Okla., Banner.