By Kim Palmer

CHARDON, Ohio (Reuters) - Suspected Ohio high school shooter T.J. Lane will be charged as an adult for the killings of three students in February and should not be released from jail on bail, an Ohio judge ruled on Thursday.

Geauga County Judge Timothy Grendell made the ruling after a hearing. If convicted as an adult, the 17-year-old could be sentenced to life in prison. He would not face the death penalty.

A Geauga County sheriff's deputy testified Thursday that Lane told him shortly after the killings that he had aimed for the victim's heads because, "I didn't want them to suffer."

Lane's defense team argued that Lane should not be charged as an adult because he did not knowingly and purposely commit the crime, due to a mental defect. At a hearing earlier this month, a psychiatrist testified that Lane suffered an unspecified psychosis that included symptoms of schizophrenia.

Geauga County Sheriff's Deputy Jon Bilicic testified that he was on his way into work on the morning of the shootings when he saw Lane sitting on the side of the road, a little over a mile from the high school, holding a handgun and a knife. Lane was wearing a long-sleeved grey T-shirt with the word "killer" on it.

After Lane was read his rights, he admitted to Bilicic he shot students. "I shot people," Bilicic quoted Lane as saying. When asked why, Lane repeatedly said, "I don't know," Bilicic said.

Lane denied that he was on drugs or alcohol or that he was depressed. He said, "I have no idea" how many people he shot, Bilicic testified.

Asked if anyone had made him angry, Lane said, "No one pissed me off. I really don't get angry."

Asked if he was picked on, Lane said, "I don't have a problem with people. They don't even talk to me."

Police say Lane killed Demetrius Hewlin, 16; Russell King, 17; and Daniel Parmertor, 16; and injured two others.

(Reporting By Kim Palmer; Writing by Mary Wisniewski; Editing by Greg McCune)