Funny thing that. Despite the arrest first of two men for the murder, the charges were thrown out when the judge ruled misconduct on the part of prosecuters. Later, one of these men flipped after cutting a deal with the NSW Crime Commission and named a shooter. There were two trials; the first ended with a hung jury, the second saw Ngo convicted with the other two (the alleged shooter and the man from the first arrests) acquitted. Pretty controversial at the time. Ngo was later sentanced to life in prison, which he is still serving today.

A few years into his sentance though, he was transfered to a "SuperMax" prison, under 24 hour surveillance, and was labelled an influental person within the prison population. Some went on to claim that Ngo actually continued to play a part in politics, though this proved to be untrue.

Some have claimed that he was himself a boss, and despite some heavy allegations regarding his criminal links (some proven) hard evidence suggest's that Ngo was a mid-to-low level criminal and used young Asian gang-members as "hired muscle".
He was heavily involved in illegal casino's and gambling rings and extortion of the Vietnamese community.
As such, the street gangs were able to distance themselves from Ngo's activities, and he bore the brunt of responsiblity.
By the late Nineties, however, increased police attention saw the phenomenon of the Vietnamese street gangs fading out, and trends changed (Lebanese gangs were the next big news story) There are still, of course, Vietnamese criminals, but the vicious street gang heroin rings are much a thing of the past. They are now mainly drug importers, brothel operators and bookmaker/loansharks, operating much more low-key.

Theres some great reports on this subject, if i can just find them ill post links. A really great book to, but i dont own it and (erm..) cant quite remember the title or author...hm.