A knifeman with a history of violence and mental illness will be free within weeks after a judge said his sentencing powers were limited.
John McEwan, who had been drinking heavily, stabbed an "entirely innocent" passer-by with a 6in knife at Victoria railway station in London on February 1 last year, Southwark Crown Court was told.
Judge David Higgins jailed the Glasgow-born 52-year-old for two years and nine months today, but McEwan will serve just half of that and has already spent 15 months behind bars on remand. He is likely to be released within six weeks.
The judge told McEwan: "You made an unprovoked attack on an entirely innocent male in Victoria station, wielding a 6in blade.
"There is no doubt that your behaviour was despicable, deplorable and deeply anti-social.
"It's very obvious that many of your difficulties are the product of excessive consumption of alcohol on regular and extensive occasions."
But he said that while he was satisfied McEwan was a potentially dangerous person, it was not possible to impose an extended sentence to reflect the risk of future offending.
Such legislation can only be activated if the defendant is convicted of an offence that would merit a four-year sentence, the judge said.
He added that it would be wrong for any court to artificially increase a sentence in order to trigger that Act and also noted that McEwan was deemed ineligible for a hospital order.
Instead, the defendant was sentenced on the basis that he admitted wounding, which carries a maximum five-year sentence.
But he was cleared by a jury of wounding with intent, a charge which attracts a maximum life sentence, following a trial last November.
McEwan has a criminal record stretching back to when he was just 10 years old, involving numerous convictions for serious assaults and violence, the court was told.
He has also suffered paranoid schizophrenia for two decades.
Earlier, the court was told McEwan had repeatedly tried to ask passers-by for directions back to his native Glasgow before he launched the attack.
But they either ignored him or made it clear they could not understand his accent.
Meanwhile, passer-by Peter Gosbee, who was returning from a wedding in Brighton with friends, had been smoking a cigarette outside Victoria station.
When Mr Gosbee, a chef, went back inside the station to meet his friends, McEwan shouted: "You can't smoke in here", before lunging at him with the 6in blade, directing the blow at the victim's head.
But Mr Gosbee blocked the knife with his arm and, as blood poured from an inch-deep wound just below his elbow, McEwan staggered back to a nearby pub.
Onlookers came to the victim's aid and also pointed police in the direction of McEwan, who was later arrested.
CCTV footage showed the defendant shortly afterwards, leaning against a nearby bar with a pint in one hand, and trying to hide the knife sticking out of his pocket with the other as officers approached.
McEwan told police he had caught a train from Glasgow to Euston earlier that day and had a drink before going for a "wee in an alley".
While relieving himself, he saw the knife "just staring at me" and shoved it in his trousers.
He later found himself at Victoria station where he became "confused because of all the people around", the court was told.
So he had another beer and, realising his trip to the capital had been a "mistake", began asking for directions home.
Even after watching the stabbing on CCTV, McEwan insisted he had no recollection of the incident, the court was told.
Rebecca Lee, in mitigation, said McEwan, of no fixed address, has "long-standing mental health and alcohol problems" and was remorseful, but could offer no explanation for the incident as he could not remember it.Reuse content