The four suspects, boys aged 14 to 16, now face charges of murder conspiracy, terrorism, terroristic threats, and conspiracy to make terroristic threats. All four were arrested last week.
"We never heard definitively that it was this week," interim Principal Michele Ferner told the Courier-Post of Cherry Hill. "What we heard was the 28th or 24th of April because it was closer, and I hate to use this word, but the."
Officials became aware of the plot in March when the girls went to the interim principal's office and mentioned a 2003 movie that depicts a school shooting.
"The good news is that the system worked," Ferner told the Courier-Post. "The kids trusted the administration and the teaching staff enough to come to us with the rumors, knowing that we would investigate them."
The boys remain in custody at the Camden County Youth Center in Blackwood pending a juvenile court hearing this week. Judge Angelo DiCamillo of the Family Division of Superior Court in Camden has ordered psychological and psychiatric evaluations for all four.