(CNN) -- Ohio school shooter T.J. Lane will spend the rest of his life in prison for the deaths of three students last year, a judge ruled Tuesday.
Lane, now 18, entered the courtroom wearing a button-down shirt, but took it off early in the hearing to reveal a white T-shirt with the word "killer" written on it. The attire was similar what he was wearing when arrested by police shortly after the killings.
Given the opportunity to speak to the court, Lane made an obscene gesture at the victims' families and spoke to them using explicit language.
He smiled and smirked during much of the hearing, laughing when the prosecutor described him as an "evil person."
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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.
The defendant, the judge said, wanted to make front-page news with the attacks on other students.
"A school is a place where a student should feel safe," said Fuhry. "These juveniles were ambushed."
The mother of a wounded student now confined to a wheelchair looked directly at Lane as she told him he was fortunate so many officers were in the small courtroom.
"Because of you, our town will never be same," Holly Walczak said. "Why? Why did you do it? Why?"
Walczak said she has watched her son, Nick, suffer daily in the year since he was shot in the school cafeteria and in the hallway when he was pursued by Lane.
"You are evil. I will have to eventually forgive, otherwise you will haunt me," she told Lane.
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.
After the sentencing, defense attorney Ian Friedman said Lane's comment to the families was a "very difficult statement to hear."
Lane's sister, Sadie Lane, pleaded for compassion and prayers for her family a well as for those of the victims.
"Many families were damaged that day. Our family was too," she said.
T.J. Lane 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.
Hewlin's brother, Philip Carter, read a statement in court on behalf of mother Phyllis Ferguson.
"In our humanity, we still cannot understand why his life was taken in such a violent manner," said Carter.