Colorado STEM school mass shooter convicted of student's murder

• Among his convictions is first-degree felony murder for the killing of student Kendrick Castillo, 18, who died lunging at his attacker in order to save classmates.

Background: Erickson's convictions come after accomplice Alec McKinney pleaded guilty last year to murder, attempted murder, conspiracy and weapons charges and was given a life sentence plus 38 years for the attack — which left eight other students wounded.

• McKinney was 16 at the time of the shooting, so he can seek parole after 40 years, Reuters notes. Erickson was 18, so he's set to receive a mandatory life sentence without parole, AP reports. He's due to have a sentencing hearing on Sept. 17.

Of note: Lawmakers in Colorado have moved to strengthen gun laws in response to the Denver attack and other mass shootings.

Flashback: Colorado tightens gun laws, one month after Boulder mass shooting