A lawyer called it Jacobean; Dennehy likened herself to Bonnie and Clyde. But police have found no motive for the brutal killings

For the warehouse worker Lukasz Slaboszewski a dull Tuesday in March last year suddenly seemed a little bit brighter when he received a series of suggestive text messages from a woman called Joanna Dennehy.

Slaboszewski, a Polish national, had met Dennehy through a shared interest in drugs and drink, but her messages promised more than a quick fix or boozing session. Cheerily, Slaboszewski went to the address Dennehy gave him expecting sex. He did not live to tell the tale.

Just inside the front door of the maisonette in Peterborough (it is not clear if he was leaving or had just arrived), Dennehy launched a savage attack, stabbing Slaboszewski through the heart with a pocket knife.

If it had stopped there, Dennehy would no doubt have been caught, jailed and forgotten. But the Slaboszewski killing was merely the prelude to an extraordinary spree of violence that means Dennehy will go down in history as one of the UK's most notorious multiple murderers.

Over the next fortnight Dennehy used her pocket knife to stab to death two more men: her housemate, John Chapman, and her landlord and boss, Kevin Lee. Even more bizarrely, Dennehy then travelled 140 miles across the country to Hereford, where she tried to murder two more men – compete strangers whom she stabbed on the street in broad daylight as they walked their dogs. They were wounded but escaped with their lives.

By the time Dennehy was arrested in Hereford following a nationwide hunt, the blade of her pocket knife was stained black with dried blood. One friend said she had started to smell of blood.

Police have found no coherent, lucid motive for her attacks. She was a long-term drug user and drinker, and had frequently been in trouble with the police for burglary, theft, drug offences and minor acts of violence.

The year before the attacks she was diagnosed as having an antisocial personality disorder and after her arrest doctors ruled that she was suffering from paraphilia sadomasochism, deriving sexual pleasure from both giving and receiving pain and humiliation.

But all that does not explain her series of murders. One of the most convincing theories so far has come Karim Khalil, barrister for Gary Stretch, who helped Dennehy dispose of the bodies.

During Stretch's trial, he compared the story of Dennehy's attacks to a 17th-century tragedy in which one crime – in this case the murder of Slaboszewski – leads on to other atrocities. "Shakespeare and Jacobean writers understood how one foul deed could beget a sequence of tragic circumstances," he said.

Dennehy herself put it more bluntly, telling one friend after the three murders: "They shouldn't have pissed me off. They shouldn't have flirted with me."

The opening scene of this modern tragedy began when Dennehy walked into Kevin Lee's Quicklet office in Peterborough.

She told Lee and his friend Paul Creed that she had just been released from prison, where she had served a sentence for murdering her father because he had abused her as a girl, and needed somewhere to live. It was true she had recently been freed from jail but the rest of her story was a lie. Her father, Kevin, is still alive – and he did not abuse Dennehy.

Creed took an instant dislike to Dennehy. "I did not want to house her," he said. But Lee was more sympathetic. "Mr Lee's attitude was she had been honest with us and he wanted to give her a chance," said Creed.

Dennehy moved into a scruffy bedsit in a modern townhouse and began doing jobs for Lee, renovating properties and leaning on troublesome tenants. Though she was slight of build, she was known to have a fierce temper and won a reputation as someone not to cross. The relationship with Lee, a husband and father of two, also developed into more than that of landlord and tenant, and they began an affair.

On 19 March 2013 Dennehy sent those messages to Slaboszewski, inviting him to meet her at another of Lee's properties and the bloodshed began.

If the killing was brutal, how Dennehy treated Slaboszewski's body was callous. Dennehy enlisted one of her friends, a career burglar called Gary Stretch, who stands 2.3 metres (7ft 3in) tall, to help dispose of the corpse. One acquaintance said Stretch used to follow Dennehy around as if he was a puppy and she his master.

At first Slaboszewski's body was stored in a wheelie bin outside the maisonette. She even showed it to a teenage friend. "Jo was just standing by the bin. She kept smiling," the friend said.

A couple of days later Lee helped Dennehy and Stretch buy a green Vauxhall Astra – which Stretch dubbed "the hearse" – and they used the vehicle to dump Slaboszewski's body in a ditch on the outskirts of Peterborough.

Police believe Lee knew why Dennehy needed the car. After helping her, he confessed their affair to his wife, Christina. Mrs Lee told her husband to stay away from Dennehy for his own safety. Like many of the men who were drawn to Dennehy, he could not stay away.

In the early hours of Friday 29 March – Good Friday – Dennehy stabbed her housemate John Chapman. He had been taking drugs and drinking, and had little chance to defend himself. She later claimed to one friend that he had stared at her while she was washing in the shared bathroom. Another possible motive could be that Lee had wanted to sell the house and needed to clear it. Chapman had told a friend Dennehy had said she would get him out of the property "by any means".

Dennehy contacted Stretch and told him: "Oops, I've done it again." He helped her to clear up, together with another friend and housemate called Leslie Layton. Chapman's body was dumped in the same ditch as Slaboszewski's.

At about the same time Kevin Lee was in town buying CDs (Bobby Womack, the xx and Justin Timberlake) and cards as Easter presents for his wife and for Dennehy.

Lee had a chat with a friend and told him about his troubling relationship with Dennehy, confiding that she "wanted to dress me up and rape me". He dropped off two CDs at home – then drove to the address where Slaboszewski had been killed to meet Dennehy. She stabbed him on his arrival.

Yet again the motive is hazy. Stretch had told a friend that Dennehy was angry that Lee had not paid her for work she had done and he was "harassing" her. Stretch warned the friend: "She will fucking kill him."

Stretch and Layton were on standby, ready to help with the clean-up. Lee's car was torched and his body dumped in a second ditch. When a farmer found it the next day, it was clothed in a black sequinned dress, his buttocks exposed. Police believe this was an act of post-death "humiliation".

When they heard the body had been found, Dennehy and Stretch fled. They visited a former cellmate of Dennehy's, Gillian Page, in north Norfolk. Page said Dennehy was excited when she saw a police television appeal for information about them. Dennehy was "jumping around" in excitement and joy, said Page. "Jo was ecstatic about it," she said. Dennehy told Page she knew they would be going to jail "for a long time" and compared herself and Stretch to the American outlaws Bonnie and Clyde.

But Dennehy was not finished. She and Stretch picked up another man, Mark Lloyd, and they set off for Hereford. Lloyd said Dennehy told him: "I've killed three people; Gary's helped me dispose of them and I want to do some more. I want my fun."

By Tuesday 2 April they were in Hereford, where Dennehy posed provocatively for a photograph with a jagged-edged knife.

Lloyd said she ran her hand down his neck. "It was like being touched by a rattlesnake," he said. But like Stretch, Lee and Slaboszewski, he was enthralled by Dennehy. "If she had told me to put my head through the windscreen I would have done," he said.

In Hereford, Dennehy's first target was a dog walker called Robin Bereza. He was stabbed twice before he realised what was happening. "I said: 'What are you doing?' She said: 'I'm hurting you. I'm going to fucking kill you.'

"She just stared right through me. I kicked her and made contact. It had no impact on her. She just came straight towards me. I ran into the road. I put my hand to my jacket and saw all this blood," said Bereza. The attack only stopped when a passerby intervened.

It was like a horror film, Lloyd said. "She strikes him like in the film Psycho. Thrusting and putting her whole weight behind it." Lloyd said she kissed Stretch on the cheek as she got into the car "as if to say thanks".

Lloyd went on: "Afterwards, Gary drove off very, very calmly. It was as if they had just stopped for a McDonald's."

Dennehy's final victim was John Rogers, who was walking his dog on a cycle path. He felt what he thought was a punch in his back. "I turned around and saw the woman who stabbed me just standing there," he said. "She started stabbing me in the chest."

He asked Dennehy: "What's this all about?" She noted he was bleeding and added: "I better do some more."

Rogers said: "She didn't seem to be showing any emotion. She didn't seem to be enjoying herself. She just seemed like she was going about business." He fell to the ground. "As I lay there, I thought: 'This is where I'm going to die.'"

Lloyd said that by this time the blade of Dennehy's knife was as "black as the handle" with blood. He said Dennehy "stank" of blood. Both Hereford victims were taken to hospital by air ambulance and their lives were saved.

Later that day Dennehy and Stretch were arrested and the next morning the bodies of Slaboszewski and Chapman were found. While psychiatrists and criminologists will pore over Dennehy's life and times in search of answers, Stretch summed her up in simple terms during a telephone conversation he made to a former partner while awaiting trial in prison. Asked why she had committed the crimes, he replied: "Well, she's just that way. You know what I mean – she's just off her head."