By John Silvester
THE man in the witness box doesn't look like an institutionalised inmate and one of the most dangerous men in Australia.
In his well cut shark-grey suit and matching tie he could pass for a fitness-conscious stockbroker: the type that chooses the shaved head look favoured by many modern metrosexuals.
Matthew Johnson in the clothes he has worn most of his adult life.
There are no signs of jail tattoos, body piercings or battle scars to hint at the man's 20-year criminal history that now includes 159 criminal convictions - the last added yesterday when a Supreme Court jury found him guilty of murdering underworld identity Carl Williams inside Barwon Prison.
Yet at his first appearance to testify there are signs that the outfit is not the witness's daily business attire but clothes bought to impress the jury. On the sleeve of the brand new suit are four spare buttons, still loosely attached by a piece of tailor's cloth. The back slit on the jacket is held together by a single temporary stitch - a sure sign it is fresh from a store rack rather than a private wardrobe.
Over three days in the witness box, Matthew Johnson stuck to his improbable story, that he killed Williams in self-defence. His barrister, Bill Stuart, argued through the trial it was a case of ''kill or be killed''.
Such a position was somewhat eroded when the jury saw prison video of Johnson attacking Williams from behind on April 19 last year, beating him eight times over the head with the metal stem of an exercise bike and dragging him into his cell.
There they saw Johnson in the clothes he has worn most of his adult life: the prison garb of red T-shirt and shorts.
In the witness box, Johnson maintained he believed Williams was planning to kill him using four billiard balls inside a sock as a weapon. His voice was controlled, his answers measured and his version of events - totally unbelievable.
Even Johnson didn't seem confident the jurors would swallow his story. ''The moment I made up me mind to kill Carl, I just assumed that the next 30 to 40 years I'm spending in jail,'' he told them.
The exact number of years will now be decided by Justice Lex Lasry at a later sentencing date but Johnson's estimation seems certain to be around the mark.
When the jury of seven women and fivemen returned their verdict after 14 hours of deliberation, Johnson showed no emotion. The decision would hardly have surprised the career criminal who knew this day was coming from the time he launched his premeditated attack 19 months earlier.
From 1999 until 2004 Williams was one of the top three Melbourne underworld figures on the outside. He had declared war on the Moran family and embarked on a campaign to exterminate anyone connected with the crime clan. And his justification mirrored Johnson's own hollow argument for self-defence. ''I was in a kill or be killed situation,'' Williams wrote to his mother, Barbara, in 2008.
The crime world is broken into life on both sides of the prison walls, and on the inside Johnson is a major power. With little else to do but build muscles with jail weights, and a network of aligned inmates in a group called Prisoners of War, he has a fearsome reputation. On the outside Johnson was a just a soldier. On the inside he is known as The General.
Even on the outside Williams's power base had been destroyed. The former supermarket shelf stacker who once made $100,000 a month through drugs was broke. Many of his violent associates had turned on him or were dead and those who had been jailed were kept in different sections of the prison system to ensure he couldn't rebuild his influence.
As an underworld player, Williams was already yesterday's man. His mother had committed suicide, his wife, Roberta, had a new partner and his ailing father, George - who at one time shared his prison unit - had been released.
Interestingly, George gave evidence at the trial that after his release he put $190 a month in Johnson's prison account. Whether this was an act of sympathy or insurance is not known. Either way it didn't work.
From the moment Williams entered the prison system, after his arrest for conspiracy to murder on June 9, 2004, he was judged to be at high risk - for more than one reason.
The Morans had many friends inside who might want to square the ledger, and high-profile inmates are always potential targets from ''wannabe gangsters'' keen to build a name.
And when it became known the one-time underworld kingpin was trying to cut a deal with police by providing information over the May 2004 murders of police informer Terence Hodson and wife Christine, the risk to Williams's safety rose dramatically.
Williams was housed in the top security section of Barwon Prison and only allowed to associate with two or three inmates. Senior prison officers were told to constantly monitor interaction between inmates and at the first sign of conflict move any prisoner who may be seen as a threat.
This Big Brother approach infuriated Williams, who asked to be placed in a less confined part of the jail. ''The authorities are being aloud [sic] legally and systematically to destroy my body & my mind,'' he complained.
Previously, when Williams was kept in solitary confinement for his own safety, he said: ''I know the authorities won't be happy until they've pushed me over the limit. But they are wasting their time. They won't succeed - that I can assure you.''
So he was moved, partially to keep him happy while he was talking to police. It would prove to be a spectacularly inept decision. Despite the fact that Williams was seen as a high-risk prisoner who could provide information on Victoria's most important double murder, he was placed in a unit with Johnson - a massive man with a well-earned reputation for explosive violence.
The system, combined with his personality and past, conspired to leave Johnson with little regard for human life. He was once charged with (and acquitted of) murdering a teenager over a $50 drug deal, and shortly after he killed Williams he told a prison officer: ''Boss, what's the big deal? People die every day. What are you making a fuss about it for?''
Discipline inside a maximum security prison, where the guards are always outnumbered by the inmates, runs on a simple carrot and stick approach. Good behaviour results in early release, and bad behaviour in tear-gas, loss of privileges and extra jail time.
The most dangerous inmates are those who don't care. Physically tough, they see prison as their natural home. They no longer fear punishment - they expect it.
In the 1970s it was Mark ''Chopper'' Read, a man whose criminal record on the outside was unremarkable and yet he became the most feared figure inside Pentridge's notorious H Division.
Read was eventually stabbed in Pentridge and seriously wounded. One of the men who turned on him was double murderer Greg ''Bluey'' Brazel. Brazel was eventually bashed and seriously injured by a prison gang led by Matthew Johnson.
The self-defence argument has often been used for jailhouse murders. Usually the survivor slashes his arms a few times to suggest defensive wounds and has a fellow inmate swear the victim struck first.
But Johnson was in a high-tech prison and video footage would show it was a premeditated attack. The video also exposed another truism of jail - it is mind-numbingly boring. Day after day the same faces do the same thing at the same time - that is, until someone snaps.
The prosecution decided it did not need to explore a motive to prove its case against Johnson. But the reasons for the murder remain of great interest to police in the Driver taskforce.
What they want to know is why Johnson, 38, was prepared to commit a murder when he must have known there was virtually no chance of him getting away with the crime? And why would he sacrifice decades of his life, to be spent doing hard jail time, by killing a man who could not harm him and would soon have been moved to another part of the system?
It is an established fact that soon after Williams was murdered, charges over the Hodson murders that had been laid against former drug squad detective sergeant Paul Dale and a convicted killer were dropped.
The Hodson connection remains an avenue of inquiry for the Driver taskforce but it is not the only one. Driver detectives have a list of those with prison contacts who would benefit from Williams's death. They include his known enemies, but also one-time friends who would have feared what he had to say when he made statements to police.
So it comes down to those who feared what Carl had said, or what he might have been going to say.
One of the rules of the underworld is that dead men tell no tales. But the question remains: has Carl left enough clues for Driver to follow the trail?