A jilted former City worker found guilty of orchestrating a campaign of harassment against a doctor and her mother faces jail.
Al Amin Dhalla, 42, moved into the home of Dr Alison Hewitt, 35, in Brighton, East Sussex, months after meeting her through an elite online dating agency for professionals.
But relations soured after Dr Hewitt's family voiced concern over his "unseemly haste" to marry her and over lies they uncovered about Dhalla's past.
The couple split after a year, triggering a terrifying four-month campaign by stalker Dhalla in which he tried to burn down her mother and stepfather's home and hired a private investigator to snoop on her.
Yesterday at Lewes Crown Court, ex-City auditor Dhalla was found guilty of seven counts, including arson being reckless as to whether life is endangered, attempted arson, harassment of Dr Hewitt and her mother, theft and damaging property.
He was found not guilty of two counts of the more serious charge of putting a person in fear of violence by harassment.
Today, following further deliberations, jurors also convicted Dhalla of perverting the course of justice, having an offensive weapon and found him not guilty of another theft charge.
Dhalla stalked Dr Hewitt by posing as a doctor at the hospital where she was due to start work and asked to see the trainee doctors' rota.
He also bought two mini-crossbows and a 1.77 air pistol with ammunition for both and a van specially adapted to include a cage in the rear.
At the height of the harassment, police airlifted Dr Hewitt's mother Pamela Hewitt and stepfather David Gray from their holiday home on Lundy Island off the Devon coast amid fears for their safety.
A senior detective believes they foiled Dhalla - described by Miss Hewitt's family as a "narcissistic psychopath" - from committing three murders.
The trial heard that Canadian national Dhalla came to Britain in 2009. A year later he met Dr Hewitt through a London-based internet dating agency.
Prosecutor Richard Barton said he moved himself into her home in Church Place, Brighton, but cracks soon appeared in Dhalla's claims about his background.
Due to Mr Gray working in the defence systems industry, he required security clearance and had to tell his employers about any changes in his family's circumstances.
Through his own inquiries and those of his employer, it emerged that Dhalla had lied about his past.
He falsely claimed that he was 35, an orphan and had lived in Britain for several years. He also did not mention a conviction in Canada for assaulting his uncle with a weapon.
His lies led to him being suspended from his job in December 2010 and in the same month Dr Hewitt decided to end their relationship.
The court heard that Dhalla's behaviour turned increasingly erratic and sparked a manhunt involving five police forces. He at first refused to move out of her home, forcing Dr Hewitt's relatives to evict him.
Days later, poison pen letters started being received by Dr Hewitt's NHS employer, where she was a trainee doctor, maliciously claiming she acted in a criminal way.
Neighbours of Mrs Hewitt and Mr Gray in the upmarket village of Aston Abbotts, near Aylesbury, Buckinghamshire, were also sent anonymous vindictive letters.
Over the course of the next few months, Dhalla's behaviour became increasingly threatening towards both Dr Hewitt and her family, Mr Barton said.
In one incident, he stood in the middle of the road and blocked her path as he pleaded with her to give their relationship another chance.
On April 1 last year, Mr Gray and Mrs Hewitt went on holiday to Lundy Island, with only a few friends and family knowing where they were heading.
The next day, after buying a .22 air rifle and a 1.77 air pistol and two mini crossbows, Dhalla was arrested in a field near Chippenham, Wiltshire, while target-practising.
Inside his specially-adapted van were masking tape, tools and details of locations, said by the prosecution to include Mrs Hewitt's and Mr Gray's holiday spot, their home addresses and hospitals where Dr Hewitt worked.
He was charged with offences related to discharging the weapons and freed on bail, a decision described by detectives as "regrettable".
Days later, while Mrs Hewitt and Mrs Gray were still on the island of Lundy, he torched their thatched cottage in Buckinghamshire.
After dousing newspapers with petrol, he set fires by the front and back doors but no one was hurt, although people were asleep in neighbouring homes.
Such was the concern by police for Mrs Hewitt and Mr Gray at this point that they airlifted the couple off Lundy Island to safety.
The case took a further dramatic twist when, a few days later on April 7, Dhalla was spotted at the Princess Royal Hospital in Haywards Heath, West Sussex, by Dr Hewitt's new colleagues.
Posing as a doctor, he was trying to lay his hands on the trainee doctors' rota, including the times when Dr Hewitt would be on duty.
On the same evening, he hired one of a series of cars to drive back to Buckinghamshire.
But in a fit of frustration at seeing his ex-girlfriend's family home surrounded by police, he drove to a nearby police station at Wing instead and tried to burn it down.
Dhalla then visited Dr Hewitt's hospital workplace at 6.30am the following day, about two hours before she was due to clock on.
Staff who had been warned that Dhalla was a potential threat spotted him dressed smartly and armed police arrested him.
In another hire car parked nearby, police found a loaded crossbow, a large knife, fuel cans and a fake doctor's outfit, including a stethoscope.
Police officers also discovered razor blades, a fuel-soaked envelope addressed to Mrs Hewitt and a folder containing the trainee doctors' rota.
He was charged and remanded in custody until his trial but while on remand he sent Dr Hewitt letters, prompting prosecutors to charge him with perverting the course of justice.
Bringing Dhalla to justice involved a "unique" partnership between five forces: Sussex, Devon and Cornwall, Wiltshire, Thames Valley and the Metropolitan Police.
Judge Charles Kemp adjourned sentencing to April 16 and requested psychiatric and probation service reports.
Dr Hewitt told reporters that ministers should take note of her disturbing case and she called for harassment laws to be updated.
She said: "I ask that those involved in debating stalking and harassment laws look at this case. It is another example of how important it is that harassment laws are updated.
"Stalking destroys lives and we need to take it seriously. If it is not, it will be somebody else tomorrow, maybe even yourself."
Dr Hewitt choked back tears as she urged anyone who faces a similar ordeal to speak to the police immediately.
She said: "My message is to anyone out there who has been harassed or stalked.
"If you try to control the situation yourself and failed, if your family and friends have tried to help you and failed, then you need to go to the police.
"You cannot control this situation yourself. You need professional help. You must talk to police in order to get your life back and it takes time."
Detective Inspector John Wallace, from Sussex Police, said the case was the worst he had ever dealt with as he described Dhalla as "industrious, resourceful and intelligent".
He said it was "regrettable" that magistrates in Wiltshire chose to free him on bail, leaving him free to go on to commit further crimes against Dr Hewitt and her family.
Although Dhalla remained "one step ahead of us" at some points, Mr Wallace said police eventually managed to bring him to justice.
Mr Wallace said: "We lost control of him at that point. It was regrettable but we deal with whatever hand we are dealt with in terms of investigation.
"He was arrested, charged, he was released by a court regrettably, but we caught up with him."
Mr Wallace said he believed Dhalla could have gone on to kill or cause serious harm.
"This man was arming himself with lethal weapons and going to extreme measures, so I believe there was a serious risk of harm," he said.
"This is a case that really stands out from the ordinary.
"In short, he is a dangerous man.
"I don't believe that he is a danger to the wider public but someone who enters into a relationship with him and things don't work out, he poses a serious threat to them.
"It was a real challenge to catch up with him. He changed car four times. Initially he was one step ahead of us but we caught him in the end."
Detective Chief Inspector Rebecca Mears, of Thames Valley Police, said she believed police prevented three people being murdered by arresting Dhalla.