Mr. McKinney, whose legal name is Maya McKinney, said he targeted several students who “always made fun of him,‘ hated him, ’called him names and said he was disgusting for trying to be a guy,” the affidavit states. One of the students had broken Mr. McKinney’s laptop and repeatedly referred to him as “a she,” the affidavit states.
Mr. McKinney also told the authorities that he had had suicidal and homicidal thoughts since he was 16, feelings that had come back to him in the weeks before the shooting.
Prosecutors say both Mr. McKinney and Mr. Erickson fired guns they had taken after breaking into a locked cabinet at Mr. Erickson’s home.
Both were charged with first-degree murder, though it was Mr. Erickson’s shots that killed Mr. Castillo, Ms. Migoya said. Mr. Erickson and Mr. McKinney also wounded six students in the attack.
Two others were injured when a school security officer responded and shot what he thought were the gunmen, Ms . Migoya said. In fact, the officer fired at emergency responders and the bullets went through a wall and injured two students in another classroom, Ms. Migoya said.
The shooting drew national attention because it came just over two weeks after the STEM school joined hundreds of others near Denver in closing temporarily amid security concerns that coincided with the 40 th anniversary of the shooting at Columbine High School, where two students killed 16 of their classmates and a teacher.
On Friday, no one answered at a phone number listed for Mr. Castillo’s parents, John and Maria Castillo. Both attended the hearing on Friday at which Mr. McKinney pleaded guilty, and Mr. Castillo said afterward that he was relieved not to have to sit through a trial,