DAVIS, Calif. — The University of California, Davis chancellor defended herself Tuesday from criticism over the campus police force’s pepper spraying of peaceful demonstrators as information emerged about the officer at the heart of the incident.

Video footage of Lt. John Pike and another officer clad in riot gear casually spraying an orange cloud at the heads of protesters who were sitting peacefully on the ground has sparked national outrage since it began circulating online Friday night. Students gathered on campus Tuesday for the second time in as many days to condemn the violence and urged university officials to require police to attend sensitivity training.

UC Davis Chancellor Linda Katehi defended herself during a town hall meeting Tuesday night. She told an auditorium filled with more than 1,000 students that she asked police to remove tents from the university’s quad but did not direct them to forcibly remove the demonstrators.

“I explicitly directed the chief of police that violence should be avoided at all costs,” she said. “It was the absolute last thing I ever wanted to happen.”

Pike, another officer and the campus police chief have been placed on administrative leave.

Pike is a retired Marine sergeant who has been honored for his police work on campus. He has risen swiftly through the ranks of the UC Davis police force over the last decade. As one of four lieutenants, the 39-year-old supervises more than one-third of the sworn officers.

He has twice been honored by the university for exceptional police work, including a 2006 incident in which he tackled a scissor-wielding hospital patient who was threatening fellow officers. Afterward, he said he decided against using pepper spray because it might harm his colleagues or hospital patients.