The panel said the deadliest day in Oakland Police Department history - March 21, 2009 - was set in motion when the motorcycle officers ignored safety procedures by approaching the driver's side window together during a traffic stop.
The driver, parolee Lovelle Mixon, reached outside the window and shot both officers - Sgt. Mark Dunakin and Officer John Hege - then crawled out the window and shot them again in the street as they lay dying, the panel's 18-page report said.
But the mistakes mounted exponentially after the first lieutenant on scene issued a citywide call of an officer down, adding to the already chaotic situation when dozens of patrol cars responded.
"This lack of coordination contributed to an ineffective and poorly managed operation," the report said.
Oakland Police Chief Anthony Batts said Wednesday that despite the errors, there were also many good decisions, and selfless and courageous acts that day.
Batts also said some officers have been reassigned as a result of the incident.
"We will correct those areas that we were flawed in," he said. "We will improve."
The report's writers were most critical of a law officer identified only as "Lieutenant No. 3," who they say developed the plan to deploy a hastily assembled SWAT team to a nearby apartment and disregarded evidence that Mixon - also a suspected rapist - might still be hiding there.
Lieutenant No. 3 also failed to wait for snipers, hostage negotiators and a building blueprint, the report said.
"By not providing sufficient time for team preparation, Lieutenant No. 3 prematurely ordered the Entry Team to undertake a high-risk task from a position of extreme disadvantage," the report's authors wrote. "The hasty approval of this plan by senior commanders compounded this error."
Within seconds of entering the apartment, SWAT team member Sgt. Ervin Romans was fatally shot by Mixon, who was armed with an assault rifle fitted with a magazine of ammunition and a bayonet.
Rather than retreating to a safe location, according to department procedure, the rest of the SWAT team continued moving into the dimly lit apartment. Mixon then fatally shot another SWAT team member, Sgt. Daniel Sakai, before being killed by other officers.
"I don't know if they had done anything differently that the results would not have been the same," assistant chief Howard Jordan, then acting-chief at the time, said Wednesday. "Lovelle Mixon was determined, willing and capable of doing what he did."
Oakland Police Officers Association President Dom Arotzarena said Wednesday in a statement that while officers may be criticized about the incident, "the decisions were made at a time when the lives of citizens and police officers were at stake."
The panel did offer praise for the quick and courageous actions of some officers, including what it deemed a thorough and appropriate decision to cordon off streets so the suspect couldn't escape.
The report also praised the SWAT team for not shooting Mixon's sister when she ran screaming through the apartment after the first shots were fired.
The five-person panel included high-ranking law enforcement officials from the Los Angeles police and Los Angeles County Sheriff's Office, and an official from the U.S. Department of Justice. They recommended that command officers and supervisors carry pocket-sized guides in case of similar incidents and the rank-and-file receive more training.
When scores of officers converged on the shooting scene, the report said, a lack of supervision and guidance put their lives and others in jeopardy. There was no command post and no clear on on-scene commander. No senior Oakland Police leaders arrived for 90 minutes.
"As a consequence, no one knew who was in charge, adding to the growing confusion and disorganization," the report said. The report said the officers who entered the apartment were an ad hoc SWAT team that had not practiced together. They disregarded alternatives such as using telephones or bullhorns to make contact with the occupants and should have retreated when they encountered unexpected assault rifle fire, the report found.
"This is the greatest tragedy in OPD history and one of the worst in the State of California and the Nation," the report said.
City Council President Jane Brunner said the report has reopened some wounds.
"I don't know if you ever have closure after four officers were killed," Brunner said.
In 2009, the number of officers killed in the line of duty by gunfire rose 24 percent from the year before, according to the nonprofit National Law Enforcement Officers Memorial Fund. As of last month, 47 police officers were fatally shot on duty, up from 38 for the same period in 2008 - the lowest number of gunfire deaths since 1956.
