The Colorado Department of Education says it mistakenly left the Arapahoe High School shooting out of an official accounting of disciplinary action.
Parents and at least one state lawmaker were upset by the omission of the December 2013 attack. The department had provided an early copy of the disciplinary report to The Denver Post and Channel 7.
But that early version had formatting errors, says department spokeswoman Megan McDermott. "We were trying to meet the needs of a news outlet as quickly as we could," McDermott says. "It was our error; it's not the fault of anyone else."
Column headings were incorrect on the provided spreadsheet, she says.
"There was no fault on the part of Littleton Public Schools," McDermott says. "They reported that shooting incident accurately in the way they were supposed to report it. And it was just an error on our part that it wasn't reflected in that initial dataset."
The department is fixing the bad dataset and will publish it on its website soon, McDermott says. In the future, data will be checked by another staffer before it's released.
"We really regret that this happened," McDermott says.
McDermott says the department is working with Republican state Rep. Polly Lawrence, who is pushing for changes to Colorado's school violence reporting laws.
"It seems to me that it’s something that we need to clarify further, so that parents and students have a clearer picture of what’s going on in the schools that they’re attending," Lawrence says.
The shooting claimed the life of 17-year-old Claire Davis. The gunman, 18-year-old Karl Pierson, killed himself shortly after.
The school violence reporting law was created after 1999's Columbine High School shootings.