A teen shooter who wounded two fellow students when he opened fire at a Colorado high school Wednesday was only 16 year old — and “radicalized by some extremist network,” authorities said.

Desmond Holly was identified as the disturbed teen gunman who caused havoc at Evergreen High School before he turned the gun on himself and later died at the hospital, police said Thursday.

He rode the bus to school — which is about 30 miles west of Denver — and used a revolver hours later around lunchtime to rattle off “a lot” of gunshots, said Jefferson County Sheriff’s Office spokesperson Jacki Kelley.

A clear motive remains a mystery for now.

“He was radicalized by some extremist network,” Kelly said, though she didn’t provide more details.

“But we want to at least give you that much about, maybe, the mindset for him,” she added.

A driver’s license photo of the depraved youngster shows Holly flash a blank stare.

He fired from the outside of the school, with one student struck inside and the other victim hit outside, police said.

It’s unclear if the two victims were targeted or caught up in a random attack, Kelly said. Both pupils remain in critical condition.

“The suspect brought quite a bit of ammunition with him, and he continued to reload,” she said. “I think we’re very, very grateful that there were not more injuries.”

She said Holly tried to enter access to areas that were locked down, but staffers and students did a good job of following training and “kept them safe for sure.”

Windows and lockers were damaged by gunshots.

Evergreen High School is part of Jefferson County Public Schools, which includes Columbine High School, the site of one of the deadliest school shootings in 1999.

Authorities are working to determine more Holly, including searching his home, locker and phone.

It was not known yet how he obtained the weapon, according to Kelly.