According to Dorner's screed, in his time with the LAPD, he heard the "N-word" casually exchanged by his fellow officers, and watched police academy recruits taunt a Jewish colleague by singing Hitler Youth ditties. His murderous rampage, he claimed, was "a necessary evil that I do not enjoy but must ... complete for substantial change to occur within the LAPD".
The alleged killer's accusations have drawn more than 27,000 supporters to a Facebook page entitled, "We Stand With Christopher Dorner". At least three current and former black LAPD officers have come forward to say they recognise his grievances. One of them, 48-year-old Brian Bentley, said: "It was almost as if I'd written [Dorner's] manifesto myself. I experienced what he experienced."
As he announced the re-opening of the disciplinary case that led to Dorner's firing, the city's police chief Charlie Beck said: "I am aware of the ghosts of the LAPD's past, and one of my biggest concerns is that they will be resurrected by Dorner's allegations of racism."
One of those ghosts is that of William H. Parker, LA's police chief throughout the 1950s, who ran a department that was often faulted for its brutality and racial antagonism. It was towards the end of Parker's tenure that 34 people died in the 1965 Watts Riots, incited by a white policeman pulling over a black driver on suspicion of driving under the influence.
The same tensions flared again more than 20 years later, when an amateur filmmaker with a Sony Handycam shot a grainy, nine-minute video of LAPD officers beating black motorist Rodney King. In 1992 an all-white jury set free the four officers involved, sparking days of unrest that left 55 people dead. The then-police chief Daryl Gates resigned shortly after the riots.
Among the laws created later was a two-term limit for LAPD chiefs, so no one could rule the department for longer than 10 years, as both Parker and Gates had done.
Yet despite the appointment of its first African-American chief, Willie Williams, the LAPD's image failed to significantly improve in the 1990s. At the 1995 trial of OJ Simpson for the murder of his ex-wife Nicole and her friend Ron Goldman, the defence used the proven racism of LAPD detective Mark Fuhrman to suggest he had prejudiced the case.
Connie Rice, a civil rights lawyer and adviser to the LAPD chief, rejected Dorner's claim that "the department has not changed since the ... Rodney King days".
"They've made enormous changes," said Ms Rice. "You no longer have a command staff that openly embraces racist jokes and epithets, or racial hostility to minority officers. You have a police force that is no longer majority white male. ...
"But it's also true that we have a long way to go. We need more women police officers, and the LAPD is not an interracial nirvana."
- Independent