LOS ANGELES – The May Day MacArthur Park melee, in which Los Angeles Police Department officers clashed with protesters and journalists, occurred because of a series of errors by police commanders, according to a long-awaited report released Tuesday.

Officials said 26 officers are under investigation and could face discipline for excessive use of force during the incident.

The report, prepared by top LAPD officials, highlighted numerous missteps by commanders and officers before and during the confrontation:

• Deputy Chief Caylor “Lee” Carter “underestimated the size and significance” of the rally, which took place at the end of an immigration protest.

• Commanders did not take advantage of the more than 450 officers available to handle the crowds at the park, relying instead on a smaller group of elite officers who easily became overwhelmed.

• Officers appeared to use more force on journalists and protesters than LAPD policies or the law allow, the report said. “It appeared that some of the officers and supervisors in MacArthur Park believed that, contrary to department policy, baton strikes could be used to compel a person to disperse, even if they were merely standing in front of the officers, failing to respond to direction,” the report said.

• There was confusion among officers about who was in charge, with some officers saying there was tension between Carter and two other commanding officers.

The clash injured 42 protesters, reporters and police and is considered a black eye for the LAPD. TV footage showed officers wielding batons and firing rubber bullets at reporters covering the story.

Police Chief William J. Bratton has been highly criticized for the way the incident was handled by officers and ordered that officers be retrained in crowd-control tactics. He also created a crowd-control bureau and bought new technology to aid in crowd management.