The prisoner who as a teenager opened fire at his middle school in Washington state more than 20 years ago has spoken out for the first time, apologizing for killing a teacher and two fellow students.

Barry Loukaitis' hand-written letter to the Grant County Superior Court was filed last week as part of a court-ordered resentencing in the 1996 bloodshed.

"I've never apologized for what I've done," Loukaitis wrote. "I didn't because I feared that trying to apologize after doing something so terrible would only add insult to injury.

"If that feeling was wrong, I'm sorry for not speaking before," he said.

Loukaitis was 14 when he opened fire in a classroom, and he was sentenced to life in prison without the possibility of parole. But the U.S. Supreme Court ruled in 2012 that people younger than 16 could not receive life terms without parole.

Washington state is recommending that Loukaitis be resentenced to 189 years in prison. In his letter dated March 27, Loukaitis said he would not fight the move.

A hearing starts next Wednesday before Superior Court Judge Michael Cooper, the original judge in the case who came out of retirement to handle the new sentence.

Loukaitis carried a hunting rifle and two handguns into his math class at Frontier Middle School in Moses Lake on Feb. 2, 1996. He shot and killed teacher Leona Caires, 49, and classmates Manuel Vela and Arnold Fritz, both 14. Another student was wounded before teacher Jon Lane confronted and disarmed Loukaitis.

He was tried as an adult in Seattle in an attempt to find an impartial jury. He claimed an insanity defense that was rejected by the jury and convicted in 1997.

In his letter, Loukaitis described himself as a hostile and rude 14-year-old and apologized for not pleading guilty after the shootings.

"None of this should have happened in the first place," Loukaitis wrote in his recent letter. "But if it did, I could have at least have had the decency to have pled guilty instead of trying to escape justice.

"I put you and an entire community through an agonizing, senseless and expensive process in an attempt to flee from justice," he wrote.

In prison, Loukaitis has earned a high school diploma and worked as a teacher's aide.