Murder.
The point about the other things is that they show it was his intent to kill, before the event, and the events afterwards cast doubt on his claim of self defence.
What also casts doubt on his claim of self defence is that he fled the scene, hid the weapon, and lied in his statements to the police, claiming to have been, and fired from, places where he couldn't have fired from.
So you not only have his intent to kill before the event, you have attempts to conceal the facts after the event.
Doesn't really sound like self defence.
It didn't to the police, which is why they charged him with murder.
It didn't to the jury, which is why they convicted him of murder.
It didn't to the court of appeal, which is why they refused to release him, and instead reduced his conviction to manslaughter on the grounds he suffers from extreme paranoia.
English law requires only 2 things to show self defence:
1, an honest belief (which need not be reasonable, just honest) that force is required
2, a subject test that a reasonable person, who believed what the person honestly believed, would regard the force used as reasonable, with the proviso that:
"If there has been an attack so that self defence is reasonably necessary, it will be recognised that a person defending himself cannot weigh to a nicety the exact measure of his defensive action. If the jury thought that that in a moment of unexpected anguish a person attacked had only done what he honestly and instinctively thought necessary, that would be the most potent evidence that only reasonable defensive action had been taken."
That's it. You have to honestly believe force is required, and you have to use reasonable force, bearing in mind that in the heat of the moment reasonable has a whole different meaning to what seems reasonable after the event.
That's why there have only been 11 prosecutions of people for violence against intruders in residential or business premises in England and Wales in the last 15 years.
As to the difference in the Martin case being the use of a gun, no.
See for example the case of Kenneth Faulkner, who shot an intruder (John Rae) with a shotgun. Rae was sentenced to 7 year for several burglaries, Faulkner was not charged, and was praised by the judge at Rae's trial.
The problem in the UK is the perception of the law, not the law itself.
That's down to the media, who have sensed another "campaign" they can mount, and are misrepresenting cases to do it.
Take the case of Carl Lindsay as an example. He was recently sentenced to 8 years for manslaughter. This is how his story was presented:
Man Who Killed Armed Intruder Jailed Eight Years
By Will Batchelor, PA News
A man who stabbed to death an armed intruder at his home was jailed for eight years today.
Carl Lindsay, 25, answered a knock at his door in Salford, Greater Manchester, to find four men armed with a gun.
When the gang tried to rob him he grabbed a samurai sword and stabbed one of them, 37-year-old Stephen Swindells, four times.
Mr Swindells, of Salford, was later found collapsed in an alley and died in hospital.
Lindsay, of Walkden, was found guilty of manslaughter following a three-week trial at Manchester Crown Court.
He was sentenced to eight years’ imprisonment.
After the case, Detective Chief Inspector Sam Haworth said: “Four men, including the victim, had set out purposefully to rob Carl Lindsay and this intent ultimately led to Stephen Swindells’ death.
“I believe the sentences passed today reflect the severity of the circumstances.”
Three other men were charged with robbery and firearms offences in connection with the incident, which took place in February last year.
http://news.scotsman.com/latest.cfm?id=2687311
A 25-year-old man is beginning an eight year sentence after he was found guilty of the manslaughter of a 38-year-old man who had tried to rob him.
Carl Lindsay from Walkden, Greater Manchester, stabbed Stephen Swindells after he and three accomplices arrived at Lindsay's home armed with a gun.
Mr Swindells died later after he was found discovered collapsed in an alley.
His three accomplices were found guilty of robbery and firearms offences and sentenced to fourteen years.
Manchester Crown Court heard how Mr Swindells, from Rockley Gardens, Salford, went to Lindsay's flat at 2145 GMT on 27 February 2003 with the intention of robbing him.
Robbery and firearms offences
When Lindsay opened the door, to be confronted by him and three accomplices who were armed with a gun, he fetched a Samurai sword and stabbed Mr Swindells four times.
Mr Swindells died later in Hope Hospital after he was found in an alleyway between Strawberry Road and Broad Street in Pendleton.
David Ryan, of Salford, Darren Ashton of no fixed abode and Michael Page, also of no fixed abode, were all convicted of robbery and firearms offences.
They were sentenced to 14 years.
Det Chief Insp Sam Haworth said: "Four men including the victims had set out purposefully to rob Carl Lindsay and this intent ultimately led to Stephen Swindell's death.
"I believe the sentences passed today reflect the severity of the circumstances."
http://news.bbc.co.uk/1/hi/england/3561555.stm
It was gleefully picked up by pro gun sites across the US.
What's missing from the story is the fact that Lindsay was a drug dealer. The men entered posing as drug buyers, Lindsay chased them outside repeatedly stabbing one of them in the back with a sword he kept to protect his "business".