There was a loud snort of derision in the Darlinghurst court room when sentencing judge Geoff Bellew said Roger Rogerson, the former detective he was about to send to jail for life for murder, "has no history of violent offending".

On paper that is true but the sad reality is that for years, Roger Caleb Rogerson got away with murder, attempted murder and other heinous crimes.

For those who have shaken their heads at the very idea of a 75-year-old pensioner with dodgy hips still engaging in his chosen profession as a ruthless assassin – it doesn't bear contemplating how many deaths the state's most notoriously corrupt detective got away with when young and fit.

As a police officer, Rogerson was present on two occasions when police shot and killed people, and on another two occasions he shot and killed people himself. The most famous of these was the heroin dealer Warren Lanfranchi, shot and killed by Rogerson in a laneway in Chippendale in June 1981.

And then there was his conspiracy to murder one of his own, fellow police officer Mick Drury, whose work as an undercover cop was about to dismantle a Melbourne heroin ring.

In June 1984 Drury was shot twice through his kitchen window.

The drug lord Alan Williams later testified that he organised Rogerson to offer Drury a bribe to dismantle the case against him, and when that failed he agreed to pay hitman Chris Flannery and Rogerson $50,000 each to kill Drury.

Despite Williams' testimony, Flannery and Rogerson were acquitted.

Less than a year later, Flannery disappeared. At a subsequent inquest, Rogerson was named as the prime suspect in Flannery's presumed murder.

Rogerson's career as a rogue cop came to a crashing halt in 1986 when he was finally dismissed from the service after the Police Tribunal sustained seven of nine misconduct charges against him.

In a strange twist of fate, he was jailed for setting up secret bank accounts to hide his money in the expectation he would be jailed for the Drury matter.

He was later jailed again for lying to the Police Integrity Commission.

With a life sentence, Rogerson has finally got what he deserved. It's just a pity for society that he didn't get it a long time ago.