Updated

A University of California task force said Wednesday that UC Davis police should not have used pepper-spray on student demonstrators in an incident that prompted national outrage and calls for the chancellor's resignation after online videos of the confrontation went viral.

The officers' decision to douse pepper-spray on a seated line of Occupy protesters was "objectively unreasonable" and not authorized by campus policy, according to the report by a UC Davis task force created to investigate the incident.

"The pepper-spraying incident that took place on November 18, 2011, should and could have been prevented," the task force concluded in the long-awaited report.

Officers involved in the incident said they felt they needed to use pepper spray because they believed they were surrounded by a hostile crowd, but the investigation suggested that was not the case, according to the report.

The task force also attributed the response to breakdowns in the campus chain of command, from Chancellor Linda Katehi to police Chief Annette Spicuzza to Lt. John Pike, the main officer shown in the widely viewed online videos.

The report said Pike, who was not interviewed by task force investigators, used a pepper-spray canister that was larger than the one campus police officers are authorized and trained to use.

The task force blamed the chancellor for not clearly communicating to her subordinates that police should avoid physical force on the protesters. It also said she was responsible for the decision to deploy police on a Friday afternoon, rather than wait until early morning as the police chief wanted.

UC Davis published the task force's findings and recommendations online a day after a judge approved its release without the names of most officers involved in the clash.

The task force was led by retired state Supreme Court Justice Cruz Reynoso. Its report was originally planned for release on March 6, but the campus police officers' union sued to keep the document under wraps. It claimed the report contained confidential personnel records that should not be publicly released under state law.

Alameda County Judge Evelio Grillo ruled last month that the university could release the entire report but must redact the names of all officers except Pike and Spicuzza, whose identities became known during media coverage.

In February, the American Civil Liberties Union filed a lawsuit against school administrators on behalf of a group of pepper-sprayed students seeking unspecified damages and campus policies to prevent similar responses to nonviolent protests.