A former high school student convicted of killing a teenager and injuring eight others at a Denver-area school in 2019 has been sentenced to life in prison without parole.

A toxicologist testified Friday that one of the suspects in a fatal shooting at a suburban Denver high school in 2019 was such a chronic drug user that he couldn't understand the events around him.

A prosecutor says a teen accused of killing a fellow student at his suburban Denver school in 2019 agreed to participate in the attack as long as it looked like he was pressured into participating.

McKinney, 17, is the younger of the two students charged in the May 7, 2019, shooting. The minimum sentence for first-degree murder for a juvenile is life in prison with the possibility of parole after 40 years while the minimum sentence for an adult is life without the possibility of parole. Erickson, 19, has pleaded not guilty to all the same charges McKinney originally faced in the shooting. His lawyers have portrayed McKinney as the ringleader who pressured Erickson to participate. Colorado became the 22nd state to abolish the death penalty this year but Erickson could have still been eligible for it because the shooting happened before that law was passed.