Opening statements in STEM School shooting trial bring opposing views as to Erickson's involvement Defense argues he was manipulated; prosecutors say he was willing participant (Copyright 2021 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.) David Zalubowski/AP A light snow covers bouquets of flowers placed on the sign for STEM School Highlands Ranch following Tuesday's shooting, in Highlands Ranch, Colo., Thursday, May 9, 2019. (AP Photo/David Zalubowski) and last updated 2021-05-27 21:57:45-04 DENVER â In opening statements in the trial for the second alleged STEM School shooter, prosecutors argued Devon Erickson planned out the school shooting with Alec McKinney, while his defense counsel argued that his alleged actions were a product of drug use, family trouble and manipulation at the hands of McKinney.