Graduating high school should be a magical time, but it's anything but for some students in a California town.

Parents say Quartz Hill High School, in Lancaster, left out special needs students from its yearbook.

Daniel Escobedo, 22, is one of those students. A student with Down syndrome, he's spent the last six years working toward his diploma, but he did not appear in the yearbook. His sister, Marisela, told KCAL that is simply unacceptable:

By not acknowledging him, you're not accepting him into society. Yet, you want to acknowledge everyone else....Are they not human? Are they not equal as to the other students?"

Quartz Hill principal Matt Anderson says two or three students failed to make it into the yearbook because of issues with a photographer contracted by the school. He also apologized for any problems that may have arisen and noted he didn't know specifics about Daniel's plight.

Anderson also hopes to make up for the snafu by putting together an extra page for all students whose photo did not appear in the yearbook.

As for Daniel, his sister says the school offered a refund for the yearbook, but provided no details why.