The Queen and Prince Philip pictured visiting New Zealand in 1981 as Lewis prepared to assassinate Her Majesty. Photo / Getty / Mark Mitchell
He once decapitated a sparrow, shot at the Queen in 1981 and was believed to have plotted to kill Prince Charles and Princess Diana.
Now an ex-cop has revealed how close Kiwi teen Christopher John Lewis came to killing Queen Elizabeth II.
The troubled teen came within a "finger twitch of seeing her head splatter", the former detective told the MailOnline.
Lewis had lined up the Queen and was just seconds away from pulling the trigger. However two officers walked into his line of sight, stalling the crazed teen. He later fired at her, but it went whizzing harmlessly past her head.
The self-named terrorist enjoyed describing his almost assassination attempt of the Queen, former detective Tom Lewis said.
"When I interviewed the teen he was very clear of what would have happened.
"He said he had taken up position in a place called the Octagon with his .22 rifle. He was less than 50m from where the Queen would walk past and was a crack shot.
"He told me that he had a direct shot and had her hat in his sights and was waiting for her head to splatter. He said he was just a finger twitch away from killing the Queen.
"Fortunately two police officers walked into his line of sight and he did not take the shot. Had he done so he would have changed the course of history."
The gunman later retreated to a second firing position where he pulled the trigger. He missed.
According to the former detective, who was put in charge of the investigation into the shot fired at the Queen while on tour of Dunedin, the incident was hushed up.
He told the MailOnline the New Zealand government had ordered the incident to be swept under the carpet and claimed officers who wanted Christopher Lewis charged with attempted treason were moved off the case.
At the time, attempted treason carried the death penalty. Once police became aware of the enormity of what the gunman could be charged with, detective Lewis was placed on leave.
He soon returned to work to find he was taken off the case and the charge of attempted treason had been dropped.
Gunman Lewis was eventually jailed for three years for firing a gun near the Queen as well as raiding a post office.
In 1984, the troubled Lewis attempted to escape prison in an effort to try and kill Prince Charles and Princess Diana during their royal visit.
The former detective said he has no doubt that had gunman Lewis escaped, he would have "carried out the attempt on Prince Charles and Diana".
He described Christopher as a "crazed psychopath" with a strong hatred for the Royals.
16 years later Christopher Lewis killed himself in prison.
He was described by friends as a "true psychopath" who once ripped the head of a bird "just for the fun of it".
But before he died, Lewis claimed he never intended to hurt the Queen and only wanted to scare her.
That idea was shot down when he later confessed to his partner about the assassination attempt saying: "Damn, I missed her."
When the Queen returned in 1995, Lewis was exiled to Great Barrier Island with police fearing he could attempt to kill the Queen again during her visit to Auckland.
One year later he was arrested and accused of the brutal murder of Tania Furlan.
The remainder of his childhood was turbulent, marred by physical abuse, bullying and juvenile crime.
October 2, 1981 Lewis, 17, breaks into a gun shop with two friends and steals a number of weapons – his first major crime.
October 9, 1981The three boys raid a local post office, hold staff at gunpoint and steal $5000 – they planned to use the money to fund a "revolutionary" organisation to "overthrow" the government.
October 14, 1981 Lewis, armed with a .22 rifle, fires a shot at Queen Elizabeth II during her visit to Otago.
In his memoirs Lewis said giving the Queen "a scare", by shooting in her direction, not at her, would be a way of bringing the issues and problems of New Zealand into the public eye and perhaps draw her attention to it.
The sound of the gunshot is heard but not investigated and later reports about the gunshot are quashed by police – because of fears it would jeopardise future royal tours.
November 15, 1981 Lewis pleads guilty to 19 charges, including aggravated robbery, arson and burglary. Police discover a .22 rifle in a local reserve – but no charges of treason in relation to shooting at the Queen were laid.
He was sentenced to three years in prison and spent the last 12 months of his sentence at Lake Alice psychiatric hospital to treat his severe depression.
1983 Police alleged that, during his time at Lake Alice psychiatric hospital, Lewis plotted to assassinate Prince Charles.
1995 Lewis secretly exiled to Great Barrier Island as police fear for the Queen's safety during the Commonwealth Heads of Government meeting in Auckland.
July 26, 1996 Tania Furlan found dead in her Howick home. Police believe her death to be the result of a failed kidnap attempt in which Lewis was planning on holding Furlan's baby daughter for ransom.
Baby Tiffany was abducted form the house but later dropped at a nearby church.
November 1, 1996 Lewis charged with Furlan's murder.
March 5, 1997 Lewis denies killing Furlan, despite further evidence against him including signs of a ransom note to her husband.
March 6, 1997 Lewis committed for trial.
September 23, 1997 Lewis found dead in Mt Eden prison.
December 1997 Christopher John Lewis' book is published by Howling at the Moon Productions. He had sent a manuscript to the company while awaiting trial, but was told the company couldn't publish the story while it was before the courts.