Members of Emily's family cried out from the public gallery as the jury foreman read out the verdicts.
Turner, wearing a smart suit, open neck shirt and handkerchief in his top pocket, mouthed the word 'f***' and shook his head.
The self styled 'gangster' met Emily on a double date in December 2010 and they quickly became boyfriend and girlfriend.
However, he became increasingly suspicious Emily was having affairs during their four month relationship and began fantasising about killing her.
Public school educated Turner had gone "absolutely nuts" after he found flirty messages on Emily's Facebook account and threatened to kill her with a lump hammer.
The trainee insurance underwriter also "flipped out" when he saw photos of her with "Cheeky Buff Butlers" as part of a modelling assignment.
Prosecutor Timothy Mousley QC said : "He's remorseless, he's controlling, he's possessive and he's vicious."
Turner practiced strangle holds on his friends so tightly they "began to panic and couldn't breathe."
He even told friends he had murdered Emily with a hammer on the night before her murder.
EVENTS LEADING UP TO MURDER
On May 6 last year, the night of Emily's death, the pair had gone to Cafe Shore, in Sandbanks, Dorset, and had a fight after Turner accused of her of being a "whore" because of what she was wearing.
He then took Emily back to his parents' home in the affluent area of Queens Park, Bournemouth, Dorset, where they had an argument and he strangled her in his bed during the early hours of May 7.
Turner claimed in court he had squeezed Emily by the neck but didn't mean to kill her.
He then wrote a confession letter and packed his suitcase and passport.
That morning he told his parents and the three concocted a plan claiming Emily had gone to sleep as normal but had never woken up.
His parents destroyed the confession note with bleach and removed a jacket their son had worn on the night of Emily's death.
Suspicious police officers arrested the trio and installed bugs in the family home between May 18 and June 14 last year.
The family were bailed and the secret equipment recorded them talking about "fabricating evidence and being worried about lying to police."
Police scans of computers seized from the home found Google searches for 'death by strangulation' and 'how to get out of being charged for murder.'
Pathologists who examined Emily's body found injuries consistent with asphyxiation, Turner had scratches on his arm and Emily had his DNA under her fingertips.
Today a jury of 11 men and one woman took nine hours at Winchester Crown Court to find the trio guilty.
During the trial Turner denied murder and had admitted perverting the course of justice by trying to get his mother to change her story.
He was found guilty of murder by a unanimous verdict.
His parents had both denied perverting the course of justice but were found guilty by a majority verdict.
High Court judge Linda Dobbs will sentence Turner tomorrow and said he will receive a life sentence with a minimum of 15 years.
She released the parents on bail and adjourned their case for sentencing reports but warned they can expect to receive a jail sentence.
EMILY'S PARENTS: 'I HOPE HE SUFFERS'
Outside court, Emily's father, Mark Longley, said Turner had caused a 'deep, deep sorrow.'
He added: "I hope he suffers every day in prison for what he's done."
Reading a statement from him, Emily's mother Caroline and sister, Hannah, he said: "These last five weeks have been all about finding justice for Emily and that has been done today.
"Caroline, Hannah and I have been in limbo for the last year.
"What we have heard has shocked and disgusted us.
"That a man so evil can treat a gentle, loving girl like Emily so violently is beyond belief.
"Emily was a strong willed girl who at times could be challenging to a parent.
"She was also a loving, caring and beautiful girl who lived to have fun and she loved life.
"She came to England to study and we are proud of the fact she had come half way around the world to make a better life for herself.
"That is the life that Turner decided to end.
"We heard from Turner's defence that he was a bullsh****r and even his mum didn't take his texts to her saying he wanted to break Emily's f***ing neck seriously.
"Perhaps if someone had taken those threats seriously Emily would still be with us today.
"Turner has caused deep, deep sorrow in two countries on opposite sides of the world.
"Emily's family have lost their daughter and we have a deep hole where she once was.
"We are facing a future without our beautiful young girl and it's a daunting thing but that's something we will concentrate on.
"Turner took our daughter when she was on the cusp of adulthood and we still love her very much."
He added: "I personally hope Turner suffers every day in prison for what he has done."
Caroline said: "Turner has shown no remorse and it proves that Emily was just a trophy to be adorned on his arm.
"I think his parents were put in a very difficult position and they were obviously manipulated by him.
"There comes a line that you do not cross and they over stepped that line. They have been punished for it."
In an earlier interview with the BBC she revealed Emily had texted her about Turner's 'controlling, threatening behaviour' just hours before she was killed.
She said: "I said to her if his behaviour is like this already it's only going to get worse.
"We left it at that and then, three hours later, she was dead."
She added: "She died, basically alone in that room.
"We've heard how he did whatever he did to her and then walked away and left her.
"Her hair was like a halo around her. I will always remember Emily as a radiating angel, she's just my angel."
EMILY'S HISTORY
Emily was born in Britain but her family emigrated to New Zealand when she was nine and she was raised in Auckland.
She had returned to live with her grandparents in Bournemouth, to study for a business national diploma at Brockenhurst College, Hants, and worked part-time at Top Shop in Bournemouth.
She was also signed up to a modelling agency and had appeared on the front page of a magazine in New Zealand.
The court heard Turner had received a harassment warning letter from the police to do with ex-girlfriend Sophie Latimer-Sayers and had tried to break into the home of another ex, Laura Niven.
While seeing Emily, Turner went to clubs and bars with his rich friends, who called themselves 'The Firm,' to pick up and sleep with other girls.
