MARIEMONT, Ohio — A Colorado Springs adult and a 14-year-old from Ohio conspired to carry out a “mass casualty event” at a high school in the city of Mariemont, according to law enforcement officials in Hamilton County.

The teenager, whose identity has not been released because he is a minor, has been arrested and charged after having a “credible plot to harm students and staff,” Hamilton County prosecutor Melissa Powers said Thursday.

The teenager had a hit list naming at least eight students and one teacher and planned to carry out the attack with a firearm he had recently acquired from his household.

During a news conference, Powers showed text messages between the teen and the Colorado Springs adult, in which they exchanged ideas pertaining to killing, rape, and the use of gas as a weapon in their planned attack.

Other messages detailed their plan of taking out the front office first as well as the use of a second gun.

The plan came to light when another student at the school told his father, Zach Swallen, that the teen was planning the attack on his school. His dad told our ABC-affiliate in Cincinnati, WCPO-TV, that he told authorities about the plan despite being threatened not to do so by the alleged shooter directly.

“The kid had the firearms and had a very elaborate plan and had every intention of carrying out that plan,” said Swallen. “My son, he doesn’t lie. He’s very literal, I could tell by his tone. And it was told to my son that if he disclosed anything about the plan to anybody, he would be shot and killed. But my son literally told me he didn’t care if he got killed as long as he could protect his classmates.”

Powers said she has requested that the suspect be bound to adult court, where if convicted, could spend life in prison. The 14-year-old will appear in court Wednesday, Feb. 21.

WCPO-TV has contacted the family of the 14-year-old charged, but they have not responded to interview requests.

No arrests have been made with the individual from Colorado Springs.

This is an ongoing investigation.

Denver 7+ Colorado News Latest Headlines | February 9, 11am