Wearing a white T-shirt with the word "killer" written on it, Lane declined to allow his attorneys to present evidence on his behalf at the sentencing hearing before Geauga County Common Pleas Judge David L. Fuhry.
Lane pleaded guilty last month to three counts of aggravated murder, two counts of attempted aggravated murder and weapons-related charges in the February 27, 2012, shooting at Chardon High School in northeastern Ohio.
Prosecutors agreed to drop the possibility of the death penalty in exchange for his guilty plea.
He was known by many around Chardon High, 30 miles east of Cleveland. But at the time of the shooting, he was there to be transported to Lake Academy Alternative School in nearby Willoughby.
Lake Academy describes itself as a school for "at-risk" students who are "reluctant learners" struggling with problems such as substance abuse and mental health issues.
After the shooting, an assistant football coach chased Lane out of Chardon High, and police arrested him nearby a short time later.
It was too late for Daniel Parmertor, 16, who died in the shooting.
Demetrius Hewlin, also 16, died a day later from his wounds.
And Russell King Jr., 17, who was initially declared brain dead, passed away soon after.