'Detectives determined that not only was there a plan but the five students accused would meet in the mornings and at lunch to discuss the details of the plan,' police spokesman Sgt. Pete Dugan told KHBS.
'Each meeting got further involved in the planning process, and the last meeting was when they decided to bring the weapon.
'They had even decided where the murder would take place, somewhere off campus. These meetings went on for about a week.'
School staff found the knife in the student's possession.
Police haven't release details of the motive for the plot, saying only that the group was having problems with the student who was their alleged target.
'It was not a random act,' Dugan said. 'They were targeting someone who hung out in the same group as them. Someone they were having problems with and decided to kill.
'We were able to stop it before it happened, and it was to the point where we thought it would happen,' says Dugan.