An 18-year-old high school senior spent Sunday in jail after collecting bomb-making supplies, in an attempt to attack his school.

Ryan Schallenberger’s parents called police on Saturday, when 10 pounds of ammonium nitrate were delivered to their home in Chesterfield.

They also discovered Ryan’s hate-filled journal, in which he detailed the plot of the attack and expressed his admiration for the two teenagers who killed 15 people in the 1999 shootings at Columbine High School in Colorado.

The journal, which Schallenberger kept for about a year, included maps of the building where he was studying and revealed that he was going to commit suicide after his plan was fulfilled.

The teenager had gathered enough supplies to kill dozens of people at Chesterfield High School, with bombing devices containing ammonium nitrate, an explosive used in the Oklahoma City bombing in 1995, when 168 were killed.

The town’s police chief, Randall Lear, reported that Schallenberger had also left an audio tape that was supposed to be played after his death, in which he explained the reasons of the bombing.

According to the Associated Press, Lear did not reveal what exactly was on the tape, but he said Schallenberger surely was an angry young man.

"He seemed to hate the world. He hated people different from him — the rich boys with good-looking girlfriends," Lear said.

Investigators have not yet found whether Schallenberger’s attack plans had any connection with the nine-year anniversary of the Columbine shootings.

Police interviews with family and friends described Schallenberger as one of the high school’s top students, with ambitions for college. He appeared to be a handsome and social young man.

On Monday, security was tightened at Chesterfield High School. Bomb and drug sniffing dogs have been brought to enhance security until the things come back to normal, although the police chief said he did not expect any problems to occur.