OCEANSIDE (CBS 8) - Chilling new details have been revealed in the case against an Oceanside teen accused of threatening to carry out a shooting at his school, Ocean Shores High. Authorities had previously reported that the student had threatened El Camino High, but have retracted that statement. 

He faced a judge for the first time Wednesday morning, as questions were raised about his mental health.

The 17-year-old Ocean Shores High School student is accused of threatening a teacher with a written note. The prosecution said he was expelled from El Camino High School and wrote that he didn't like the teacher. The letter said the words "dead" in it. Oceanside Police also said he threatened to shoot people at the school.

Officers also found a gun holster in his possession.

The teenager's house was searched and officers allegedly found notes detailing his plans, which included mentions of ammunition, drawings of how he wanted individuals murdered, a Kevlar vest, helmet, ski mask and cell phone videos of him firing rifles. There was also a text on his phone that said he had a concealed firearm in a public place the day before the threat.

He allegedly had a getaway plan and messages that showed sympathy to others who were captured in violent acts against schools.

According to the prosecution, he may belong to a secret militia.

The defense requested that he be released on home detention even though he was expelled for a similar incident in 2013. That request was denied, as the judge is concerned for the teen's and public's safety.

"In juvenile court we always worry about the safety of the minor and the safety of the public based on the facts and circumstances of this case. It was the decision it was not safe for the minor to be released home for his safety or the safety of the community,” said Deputy District Attorney Michele Linley with the Juvenile Division.

The minor faces two felony charges for criminal threat or bodily harm and threatening a school official, plus a misdemeanor for possession of ammunition. His defense denied all charges.

The defense plans to have their own psychological exam administered. They are also able to decide who can perform the exam and whether they release it to the prosecution.

The minor faces a "maximum exposure" (otherwise known as a sentence in adult court) of four years total until he's 21.

He's juvenile hall until his readiness hearing on May 22, 2015.