AGOURA HILLS, Calif. (KTLA) — A student upset with the athletic program may be behind racist graffiti found at Agoura High School, officials said on Thursday.

Twice over the last week, racially-derogatory graffiti was found plastered on the walls at the school.

The first incident was reported on Sunday, authorities said.

The graffiti was painted over before students showed up on Monday, and parents were not notified about what had happened.

Then on Wednesday, a so-called “hit list” consisting of five names — all African-American students — appeared spray-painted in a boys restroom.

Tensions rose and parents were upset, but on Thursday, there was a possible twist in the case.

The school’s principal, Larry Misel, said he didn’t believe the messages were racially motivated after all.

Authorities were investigating the possibility that the vandalism was actually an inside job orchestrated by a student or students named on the hit list.

At least one of those students was upset with the athletic program, a source told KTLA.

The student was apparently not being allowed to transfer to another school without penalty from the CIF, the governing body for high school sports in California.

CIF rules stipulate that a student must sit out for a year after transferring, unless there is an absolute and compelling need to transfer.

The student may have been trying to create the perception of a hostile environment at Agoura High School, officials said.

“What the evidence is showing us, right now anyways, is that it was purely a motivational thing,” Misel said.

School officials insisted that, based on the information they had, they believed the school was completely safe.

The investigation was ongoing. Authorities were working on obtaining surveillance video that might offer clues about the person or persons responsible.

A $1,000 reward was being offered for information leading to the arrest and conviction of the perpetrator.