DOUGLAS COUNTY, Colo. (CBS4) – The trial for the accused gunman in the STEM School Highlands Ranch shooting began Monday morning. Devon Erickson is facing charges in connection with the murder of Kendrick Castillo in May 2019.

Devon Erickson

Devon Erickson (credit: CBS)

Police say the Erickson and Maya ‘Alec’ McKinney walked into the school on May 7, 2019 and opened fire with handguns in two classrooms. Kendrick Castillo, 18, was killed when he and two classmates tackled one of the shooters. The other was captured by an armed security guard.

STEM School Highlands Ranch Shooting Scene on May 8, 2019

(credit: Michael Ciaglo/Getty Images)

McKinney pleaded guilty to murder charges and was sentenced to life in prison.

Jury selection for Erickson’s trial began Monday morning from a pool of 600 people.

Jennifer McRae