Lane, 22, of Melbourne, died Aug. 16 in Duncan. Police say three teenagers targeted Lane at random to break up the monotony of an Oklahoma summer.
Lane was shot in the back and the bullet struck two ribs and passed through Lane's esophagus, heart and lungs before stopping near his left shoulder.
"The bullet has a small caliber, is made of gray metal, with no jacket and has a round nose and visible markings that appear slightly deformed on the side," the autopsy said. Police have said
Lane was killed with a .22-caliber handgun.
The official cause of death was listed as "penetrating gunshot wound to the back."
Chancey Allen Luna, 16, and James Francis Edwards, Jr., 15, both of Duncan, have been charged as adults with first-degree murder. Michael Dewayne Jones, 17, of Duncan, was charged with using a vehicle in the discharge of a weapon and with accessory to first-degree murder. He is considered a youthful offender but will be tried in adult court.
In the days after the slaying, Duncan Police Chief Dan Ford said the older boy told investigators that the three were "bored" and decided to kill someone for the "fun of it."
Lane moved to Oklahoma to play baseball. He would have been a senior at East Central University and hoped to enter the real estate business.
Duncan is about 80 miles south of Oklahoma City.
East Central University has also announced a fund in Lane's honor, known as the Chris Lane Memorial Fund.
"When I think about Chris Lane, I think about a young man with a kind heart and a magnetic personality," said ECU head baseball coach Dino Rosato in a statement posted on the school's website. "He was a person I wanted to be around. He was a young man with great character. I am a better man for Chris having been a part of my life."