The report says Dorner's dismissal was the department's only course of action after he falsely claimed he witnessed a training officer kick a mentally ill man during an arrest.
The report concluded that Dorner, who was hired in 2005, lied when he claimed a training officer had brutally kicked a mentally ill man during an arrest. He was fired for making a false report and a Los Angeles Superior Court judge sided with the department during a 2010 appeal.
Dorner later posted an online manifesto saying the department wrongly fired him, and he vowed to wage war on police. That led police Chief Charlie Beck to order the review even as Dorner was on the run.
Dorner went on a killing spree in response to what he considered his wrongful termination. He fatally shot the daughter of an LAPD officer-turned-attorney who defended him during his administrative review, in which he was fired. He also shot the daughter's fiancé.
Dorner killed two law enforcement personnel during an intensive manhunt for him. He was eventually tracked down at a cabin near Big Bear Lake. He died in a subsequent shootout with police and sheriff's deputies that resulted in the cabin burning to the ground. It was determined he killed himself with a self-inflicted gunshot.
A second report will be released later in the year that will address issues raised by Dorner and others regarding the department's disciplinary system and the state of LAPD employee relations.
The Associated Press contributed to this report.