A JILTED woman wearing a "Scream" mask brought Hallowe'en horror to a street when she gunned down the neighbour of a love rival she had planned to assassinate, a court was told.

Psychotherapist and Hell's Angel biker Heather Stephenson-Snell went to great lengths to plan the murder of her ex-lover Adrian Sinclair's girlfriend, even taking shooting lessons, working out escape routes, devising disguises and researching her intended victim's home.

But neighbour Robert Wilkie was shot dead by Stephenson-Snell at point blank range when he left his home to investigate a noise in Holland Street, Radcliffe.

Charles Chruszcz QC, prosecuting, told Manchester Crown Court on Monday that Mr Wilkie was "simply in the wrong place and at the wrong time and for that he paid a terrible price."

Canadian born Stephenson-Snell, aged 46, of Crombie Avenue, York, denies attempting to murder Mr Sinclair's girlfriend Diane Lomax and the murder of Ms Lomax's neighbour Robert Wilkie outside his home in Holland Street in the early hours of November 1 last year.

Mr Chruszcz said that Mr Wilkie was killed when he went outside to ask the person banging on his next door neighbour's door at 12.40am to be quiet because children were in bed.

It was Halloween night and he found a woman dressed in a long hooded gown, with a Scream mask covering her face demanding to be let into Ms Lomax's home.

Mr Chruszcz said there was a scuffle when 43-year-old Mr Wilkie ripped the mask off her face to try and identify the caller and he was shot in the abdomen at point blank range with a sawn off shotgun Stephenson-Snell had hidden under the robe.

"Mr Wilkie was not her target," said Mr Chruszcz. "He was simply in the wrong place and at the wrong time and for that he paid a terrible price."

Stephenson-Snell fled while Mr Wilkie died on the pavement from massive injuries. His alleged killer was arrested after being stopped by police on a motorway in Yorkshire when officers found a blood stained sheet, a sawn-off shotgun and two knives in her vehicle.

The court heard how Stephenson-Snell had first met Adrian Sinclair in spring 2002 when he answered an advert she had placed looking for someone to dog sit her two Rottweilers at her home in York and do general handy work.

But when he left a few weeks later, the prosecution say she began making complaints about him to the police claiming he had threatened to kill her.

In July she rang police again and said he no longer posed a threat to her and she wanted no further action taken against him.

The pair embarked on a sexual relationship in summer 2002, which ended when Stephenson-Snell returned to York after attending a course in America.

Sinclair had moved to Manchester and met Diane Lomax and so ended his relationship with Stephenson-Snell, a psychotherapist who specialised in providing services for women. She claimed her father had been a British spy and was the author of the cult horror novel The Wicker Man.

She did not take news of the break up well and although Mr Sinclair told her no one else was involved Stephenson-Snell believed there was and threatened to mutilate her rival and kill Mr Sinclair.

Mr Chruszcz told how Stephenson-Snell began plaguing acquaintances of Mr Sinclair with phone calls demanding to know who the other woman was. She became such a nuisance with daily calls that one person changed their phone number and another bought a new mobile phone.

Eventually she found out about Diane Lomax and where she lived. Mr Sinclair had moved into the house in Holland Street, Radcliffe, with Ms Lomax and her sons, then aged eight and five.

Stephenson-Snell made allegations to police of paedophilia against Mr Sinclair and his new girlfriend. An investigation was launched, the couple questioned and their home searched before the allegations were dismissed.

Ms Lomax also received a phone call from a woman with a Canadian accent calling her a "filthy rotten prostitute". She also received an anonymous Christmas card containing photographs of Mr Sinclair kissing a woman whose face had been erased from the pictures and on another occasion, just before Christmas 2002, she spotted a woman in a baseball cap taking pictures of the outside of her house.

But in spring 2003 the intimidation Ms Lomax and Mr Sinclair were suffering stopped.

"Life returned to a tolerable state," Mr Chruszcz said.

But, he added, contact stopped because Stephenson-Snell had become preoccupied with taking shooting lessons.

The prosecution allege that Stephenson-Snell, who was president of an all female Hell's Angel biker gang, began making careful preparations to kill Ms Lomax. Written on paper found among her possessions stored at a friend's house were detailed plans of routes to and from Radcliffe, lists of items she might need such as clothing, money and new identity documents, details of get away vehicles and places to leave and collect possessions on the day of the "operation."

Other items at her friend's house in Yorkshire included several knives, shotgun ammunition and a copy of the Radcliffe Times.

The plans even suggested Stephenson-Snell intended to register the untaxed old Ford Escort she had been given by a friend and was going to use as a getaway car in Adrian Sinclair's name to link him to Ms Lomax's death.

The court heard from Deborah O'Brien, girlfriend of the dead man, who told how she and Mr Wilkie, who was known as Bob to his friends, had met in March 2003 and were planning to marry.

Although Mr Wilkie, a former army commando and pub landlord, had his own flat, he spent much of his time at her home in Holland Street, Radcliffe, which she shared with her daughters aged 14 and nine and her two foster children.

"He was just so kind and caring and very generous," she said, in a quiet voice, trembling with emotion.

She told the court how she was climbing the stairs to bed on Halloween night when Mr Wilkie, dressed only in boxer shorts, opened the front door and asked someone outside to "keep the noise down".

She heard a woman's voice reply "I'm staying and she won't let me in."

Ms O'Brien continued up the stairs but seconds later heard a bang and Mr Wilkie shouting "Debbie!"

She rushed downstairs and found Mr Wilkie collapsed on the pavement. At first she thought he had been stabbed as there was a knife lying in the road where a woman, dressed in a Halloween costume had been standing.

Forensic experts later found he had been shot with a sawn off shotgun though several layers of fabric. Examining the gun found in Stephenson-Snell's car when she was stopped by police they believe it had been modified using padded material and a strap so it could hang down the arm by the side of the body and be fired by tugging on the strap.

Stephenson-Snell was also found to be wearing several layers of clothing, which the prosecution allege was to make her appear a different shape and was wearing size eight trainers when her feet are only sized five and half to six.

From the witness box Diane Lomax told how she had never met Stephenson-Snell but when next door neighbour Mr Wilkie pulled off her mask she recognised her from photographs she had seen.

She said she and her children had been in bed on the night of October 31 but at 12.40am she got up to make herself a drink and then she heard banging on the door. When she looked though the door's spy hole she saw someone in a hooded gown and mask.

Her children were woken by the noise and came downstairs into the living room and she said she opened the door part way to look outside and spotted her neighbour ripping the mask off Stephenson-Snell's face. Mr Wilkie asked her "Do you know who she is?"

"I know exactly who she is," replied Ms Lomax, shutting her door. When it was almost closed she said she heard a bang and when she opened it again a few minutes later Stephenson-Snell was gone and Mr Wilkie was on the pavement. "He was on all fours gasping for breath," she said.

Proceeding