The LAPD was ordered to carry out an internal review of Dorner's 2009 firing after the former officer claimed the police force suffered from widespread racism and corruption, the Los Angeles Times reported.
Dorner fatally shot an Irvine woman and her husband and two police officers, and wound three others.
He was discovered in the mountains near Big Bear, but later died of self-inflicted gunshot wounds.
"I directed this review because I wanted to ensure that the Los Angeles Police Department is fair and transparent in all that we do," Police Chief Charlie Beck said in a statement Friday. "All of us recognize that as a department we are not perfect; nonetheless, this report shows that the discharge of Christopher Dorner was factually and legally the right decision."
The review concluded Dorner regularly lied to further a "personal agenda" while he was on the force, and lied about delays in his reporting of alleged kicks to a supervisor.
Rafael Bernardino, a member of the Police Commission, said he thought a review of Dorner's case was unnecessary because he "never even considered Dorner's claims to be realistic."