FLINT (WWJ) – New charges have been filed against one of three Michigan teens accused in an alleged school shooting plot after investigators discovered an “extremely disturbing” sex video.

Genesee County Prosecutor David Leyton says that, in addition to a charge of conspiracy to commit first degree murder and false threat of terrorism, 18-year-old Ryan Stevens is now facing charges of criminal sexual conduct and possession or distribution of child sexual activity.

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Leyton said the latest charges stem from evidence found on Stevens’ cell phone during the shooting plot investigation.

“On the cell phone they discovered a video that he had taken and directed, and that was a video of 15-year-old having sex with a 13-year-old,” said Leyton.

He called the video “extremely disturbing.”

“He’s just shooting the video and giving direction…essentially directing them as to what to do,” Leyton said. “But he does say, at some point, that he would like to get involved with the 13-year-old. But we’re not aware if that ever happened.”

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Stevens, of Linden, Michigan, remains jailed awaiting a competency hearing on the school threat charges.

He — along with 15-year-old Lamar Dukes of West Bloomfield and 15-year-old Cody Brewer of Wolverine Lake — are accused of plotting to kill a list of students at two Genesee County schools..

Police said the alleged plot was uncovered in the Linden school district, 20 miles south of Flint, and included specific targets at Linden High School and Linden Middle School.

Stevens is a former Linden student. His lawyer Ken Karasick told The Flint Journal his client did not intend to actually harm anyone and that the case appears to be one of young people not fully understanding the consequences of their actions.

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All three boys face life in prison if convicted.