The suspects accused of killing one student and wounding eight others in a Denver-area school shooting, the second mass school shooting in the country in a week, are an 18 year-old male, who friends said had been bullied and was depressed, and a minor.

Devon Erickson, 18, and Maya McKinney, 16, both appeared in court Wednesday, one day after they allegedly opened fire at STEM School Highlands Ranch. Prosecutors are planning to file charges against both suspects on Friday.

Police officers initially identified McKinney as male then later said that the suspect was female, a County Sheriff’s department spokeswoman said. A former classmate said the student was transgender, identified as male and went by the name Alec.