Lawyers for the families of two students slain at Columbine are taking their case to the US Supreme Court.
They want the high court to force the school to display religious-themed tiles painted by relatives after the 1999 high school shootings.
Attorney Jim Rouse says the school's refusal to hang the tiles on its walls violated First Amendment rights to religious freedom and free speech.
The tiles were part of a project meant to honor victims of the shootings. Twelve students, a teacher and their two teen killers died.
School officials say they removed the tiles because they violated the Constitution's requirement for separation of church and state.
Families sued the school, and a federal appeals court eventually reversed a lower court's decision to allow the tiles.