Two suspects are in custody following the deadly school shooting at a charter school near Denver.
Police say 18-year-old Devon Erickson and a juvenile opened fire at the STEM school Highlands Ranch Tuesday just after lunch.
"When we were exiting the building there was a trail of blood," said an unnamed student.
Investigators said the two shooters began firing in two separate locations.
An 18-year-old student was killed, and 8 others were injured. At least two students are still in serious condition.
Fernando Montoya told a local news station that his 17-year-old son was shot three times.
"A guy pulled I believe a pistol, I'm not sure, out of a guitar case, and start to shoot," he said.
The school, home to more than 1,800 students grades K through 12, was put on lockdown as police went on the hunt for the shooters who were both students at the school and not previously known to authorities.
"As officers were arriving at the school they could still hear gunshots as they were entering the school," explained Undersheriff Holly Nicholson-Kluth of Douglas County.
The suspects, who were reportedly armed with a handgun and other weapons, confronted law enforcement officers when they arrived. Police struggled with them to take them into custody.
Details are emerging about the lives of the two suspects.
In May of 2014, Erickson expressed hatred for Christians on Facebook.
"You know what I hate?" he said. "All these Christians who hate gays, yet in the Bible, it says in Deuteronomy 17:12-13, if someone doesn't do what their priest tells them to do, they are supposed to die," he said in his post. "It has plenty of crazy stuff like that. But all they get out of it is 'ewwwwww gays'."
John Fenton of CBS Denver tweeted that the car towed from Erickson's home has 'F*** SOCIETY' spray painted on the side. Also '666' and what appears to be a pentagram on its hood.
— John Fenton (@higuysimjohn) May 8, 2019
KMGH Denver reported that sources said the second suspect is transgender male in the midst of transitioning from female to male.
The Denver Channel reports that the motive "went beyond bullying and involved revenge and anger towards others at the school," and that one suspect "was involved in legal and illegal drug use and had been in therapy."
The shooting at STEM took place exactly a week after a gunman killed two students and wounded four at the University of North Carolina-Charlotte.
It also comes nearly three weeks after the 20th anniversary of the Columbine school massacre that killed 13. Columbine is located just seven miles from the STEM school.
Meanwhile, police are investigating a motive in the shooting and say the suspects could be charged as adults.
Erickson will appear in court at 1:30 p.m. on May 8. It's not clear when the juvenile will appear in court.