To the outside world, Melissa Shaw was a churchgoing housewife and loving mother to two little girls. But in reality, she was a ruthless prostitute capable of murder.

Michelle Burgess was the unremarkable suburban school Mum who contracted a hitman to take out anyone who got in her way.

These two women had a power over men that was so absolute, they could even command murder. They are Australia's real-life black widows.

Beau Shaw was so perfect a target for a black widow, he could have come from central casting. He’d lived a sheltered childhood on the Gold Coast. He and Melissa Shaw met at a church youth group.

"I never had a girlfriend before, and she was really the first girl who had ever taken an interest in me," Beau tells Michael Usher. "It could have been anyone really, but as a 17-year-old, as soon as a girl - any girl - took an interest, that interest was immediately responded back."

Beau was head over heels. Melissa seemed to be his perfect match - a devout, clean-living girl with the same values and life goals. Theirs was a whirlwind romance. They married just a few months later.

Chevron Right Icon 'It didn’t take too long to start to see the cracks.'

"It didn’t take too long to start to see the cracks," says Beau.

Those cracks became a chasm when Melissa made a dramatic confession just days after their wedding.

"We were on our honeymoon and she decided to come clean with me about what she had been doing for work before we were married. She had told me that she was working at a women’s refuge. It actually turns out the women’s refuge was actually a brothel at Tweed Heads. That was a hard pill to swallow."

Just like that, Beau discovered that his seemingly wholesome new bride Melissa was in fact the sultry sex worker, Savannah.

"Angry as I was, as hurt as I was, I felt like it was this new mission that had been given to me," explains Beau. "I couldn’t walk away from her because I was married to her which I felt was a covenant for life, and I needed to help this person. She wasn’t perfect. She had problems, and I felt that I could help her to be a better person, so I took it upon myself to do that."

Beau and Melissa had two daughters, but motherhood didn’t reign her in. Sex was her bargaining tool.

"She wouldn’t let me touch her for weeks on end because I hadn’t agreed with something, but if I went along with any of her ideas or plans she was an incredibly loving wife. It was not just sex, but just her whole demeanour. She was caring and loving. Disagree with her, she was as cold as ice."

"Sex as a weapon is one of the biggest tools in these women's arsenal," explains criminologist Dr Xanthe Mallett. "They either withhold it or they give it, depending on whether the men are falling into line with what they want."

Beau gave in to Melissa’s every whim. He even agreed to bankroll costly cosmetic surgery.

"She had said, 'I want porn star-looking boobs.' At the time, I didn’t think much of it. It was just a descriptive term."

Beau took out a $25,000 loan and flew the whole family to Thailand for Melissa’s breast enhancement surgery.

"Instead of just having the boob job done, she decided there were all these other things she wanted done," recalls Beau. "So she had liposuction on her stomach and on her legs and she had varicose veins removed. She had permanent tattooing around her lips and around her eyes [and] lip fillers put in. It totally transformed her body to a different person. She looked different from that point forward, and it still wasn’t enough for her."

Once Melissa had completely transformed her body, she demanded Beau do the same. She enlisted the help of bodybuilder Adam Gooley. What Beau didn’t know was that his new trainer was also his wife’s lover.

"I'd go a couple of nights a week down to the gym to work out with Adam, and we did strike up a friendship. I thought he was a genuine kind of guy and we hung out, worked out together. But things started getting messy because he says, 'Oh, you should take these steroids.' That decision put me in hospital within three months."

"The steroids sent me totally loopy. I think the term at the time was testosterone psychosis, from an excessive amount of testosterone. I went off the deep end."

"I was a broken shell. I started off with this idea that I would help her fix her little broken wing, and I ended up far more broken than I ever thought possible."

Play Video They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder. They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder.

Suburban life bored Melissa. She wanted a bigger house, more money, and the kind of excitement her husband couldn’t provide. She announced she was going back to work as a prostitute. She wanted to become Savannah once again.

"She says, 'I could go down to Sydney and work at a brothel in Sydney, and make a few thousand dollars in one weekend," Beau says. Melissa got her way. "She started working as a prostitute here on the Gold Coast at an establishment called the Pentagon Grand."

Melissa was out at all hours with clients, revelling in the sleazy thrill of her old trade. Beau became a stay-at-home dad.

"[I was] stuck in her web, stuck in my house, I never went out. I dropped the kids off to kindergarten, I came home and I sat at home. I didn't go out. I had no social connections whatsoever."

Beau wasn’t the only man caught in Melissa Shaw’s web. Bodybuilder Adam Gooley was also head-over-heels in love with Melissa.

Detective Mark Procter led the investigation into Melissa Shaw’s life and crimes.

"He lavished her with gifts like they all did," explains Detective Procter. "He was just another bloke trapped in the web."

Chevron Right Icon 'She knew what she wanted, and she believed she had a plan to get it.'

"She knew what she wanted, and she believed she had a plan to get it."

While Beau stayed at home, looking after the kids, Melissa raked in the cash. She kept meticulous notes on all her clients, always on the hunt for her next meal ticket. Sam Dhody walked through the brothel doors.

"He was a very wealthy businessman," says Beau. "They started seeing each other privately which started making her more money, and she told me that she was going to start dating - for lack of a better term - Sam, so that she could take advantage of his financial estate."

Beau finally snapped. He left Melissa, taking the girls with him. Melissa didn’t skip a beat. She moved in with Sam Dhody, and somehow convinced him to make her a company director with access to his bank accounts.

"They're the black widow in the centre of that web with all of these little males around them," believes Dr Xanthe Mallett. "They're either killing them, or they're using them."

And this black widow wanted Sam’s money. She convinced her devoted bodybuilder boyfriend Adam Gooley to kill him.

"Sam arrives home from work at 8.30 at night," explains Detective Procter. "In the driveway, he is confronted by a person with a crowbar who starts viciously assaulting him."

The savage attack was interrupted by a good Samaritan neighbour. As Gooley made his escape, Melissa called emergency services.

Vision from a police body camera shows a suspiciously nonchalant Melissa not long after the attack as Sam is being treated for serious injuries in the doorway.

"She has completely separated herself from this physically and vocally," says Dr Xanthe Mallett as she examines the footage. "This has nothing to do with her; that is the only signal that I can get from her. She has literally walked around the corner like, 'Nothing to do with me.'"

Although Sam Dhody was critically injured in the attack, he survived. But Melissa wasn’t going to fail a second time.

Play Video They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder. They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder.

Three months later, Melissa arranged another hit.

This time, all her scheming paid off. Sam Dhody was already dead when she called 000.

Sam had been shot ten times at point blank range in his bed.

Melissa lies to the police when giving evidence. "I’ve just got home. I’ve walked into the bedroom and my partner is dead. I think he’s been shot. He’s got holes in his head and he’s still in bed. I touched him and his body is cold. I can't believe it."

But she doesn’t fool the police. They’re suspicious from the beginning. They begin tracking her. She’s also brought into the station for questioning.

Detective Procter was responsible for questioning Melissa. "As soon as you confronted her with anything that was awkward or she didn't have answers, the wall would go up. There was a different Melissa and she would become aggressive, angry, make allegations about different things, [and] storm out of interviews."

Mark Procter’s team also bugged Melissa’s phone, and soon discovered the true nature of her relationship with Adam Gooly.

In his police interview, Gooley claimed he was sick and in bed at the time Sam was killed. It was a woefully flimsy alibi.

"We find footage of him at his workplace on the day of the murder," explains Detective Procter. "He says he is too sick to even pick up a gun, and he is picking up cartons of fruit and moving it around, so it pretty much shot his argument down that he was home in bed."

Then there was the forensic evidence tying Gooley to the shooting, including the murder weapon. The lovesick bodybuilder had used his father’s gun. Faced with the mountain of evidence, Gooley confessed. Next police raided Melissa’s house. She was arrested, charged and convicted of Sam’s murder.

Chevron Right Icon 'I think she just seems to accept her fate.'

"I think she just seems to accept her fate," says Detective Procter. "There were no more game plans, there were no more strategies, there was nothing. There was just deadpan Melissa, and that's the way it's been since then."

Melissa and Gooley were both sentenced to life in prison. Even today, Gooley remains loyal to the woman he loved and killed for.

"Gooley says it's him, only him, that Melissa knew nothing about it," explains Detective Proecter. "He snuck into the house and he shot him and he left."

It took many years, but Melissa’s former husband Beau has managed to rebuild his life with a new wife, Margot.

Trampling over people’s lives, undermining their self-worth, wrecking families and exploiting and manipulating men to do terrible things is stock in trade for so-called black widows. And there is no more diabolical exponent of these dark arts than Michelle Burgess.

"She wants the man, and anyone who's standing in her way will be removed," believes Dr Xanthe Mallett. "She's obviously not concerned about how that happens."

The man Michelle wanted was Adelaide tyre store manager Kevin Matthews.

Kevin Matthews met his wife Carolyn at their local surf club when they were teenagers. Together they had three sons - Kenny, Shane and Daniel.

They lived an ideal life - that is until Michelle Burgess came along. Michelle’s husband Darren worked at Kevin’s tyre store. From the moment she latched eyes on Kevin, Michelle wanted him - and his larger paycheck - for herself. She turned on the charm, and before long, Kevin was head over heels.

Major Crime Detectives Mick Standing and John Keane spent months investigating Michelle’s life and many lovers. Ultimately, they got to know her better than the besotted Kevin.

Chevron Right Icon 'She is the epitome of the black widow.'

"She's very cold and calculating," says Detective Keane. "She is the epitome of the black widow."

"Have sex with anybody, kill them afterwards," explains Detective Standing. "To me, that's what she did. Kevin Matthews thought he was onto a good thing, that the sex would never stop."

What Kevin didn’t know was that Michelle was juggling a legion of lovers.

Still, Michelle Burgess filled Kevin’s head with promises of a beautiful future together. All that stood in their way she told him was their spouses, Darren and Carolyn. There was only one thing to do.

True crime writer and author Derek Pedley is still confounded by what happened next.

"They were going to live happily ever after they were going to kill both their partners," explains Derek. "Cash in life insurance policies and live happily ever after. As a fantasy, it works really well, but in reality it didn't, and it was appalling."

Michelle made Kevin draw up two murder contracts, naming Caroline and Darren as the targets.

"Both of these pieces of paper had pictures of their respective targets," says Derek. "Then they worked [out] their movements during the day their phone numbers."

All Michelle needed now was a hitman. So she took on another lover – career criminal David Key.

"Michelle made some notes," Derek reveals. "She said essentially that she wanted both of the murders done that week, and that she wanted one of them done by Friday."

Play Video They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder. They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder.

The first victim was to be Kevin’s wife, Carolyn. Michelle and the hitman David Key drove to meet Kevin at his tyre shop.

Michelle and Key drove to the Matthews family home. Carolyn Matthews was by herself. Kevin had made sure of that, arranging to take their three boys to the video store.

"They got out of the car and walked towards the front of the Matthews home just as Carolyn came out the front door with some recycling," explains Derek. "Key strode up to her and asked her, 'Are you Carolyn Matthews?' and showed her the murder contract. [He] pointed to the picture and said, 'Is this you?' which was just bizarre."

"Michelle Burgess strikes Carolyn across the face and pushes her back into her house. She obviously is intent on going through with her plans to kill her, and wants to get her inside as quickly as possible. They back Carolyn into her tiny kitchen, all the while arguing about whether or not to kill her. You can only imagine Carolyn Matthews' absolute terror at this point. She's got no escape. This angry drug-crazed man is screaming at this woman in front of him, and that's when the Wiltshire knife comes out of the kitchen."

Chevron Right Icon 'You prove to me how much you love me. Kill her.'

David Key disclosed the following in police interviews: "Michelle just handed me a knife and said, 'Right now, kill her.' I said, 'You fucking do it.' She said, 'No nom you do it if you want to be with me. You prove to me how much you love me. Kill her.'"

Michelle and David Key drove to a nearby beach, where they washed off Carolyn’s blood. Meanwhile, Kevin had just arrived home with his boys, aged just 12, 13 and 16. He knew exactly what they would find inside - and yet he deliberately held back, letting his children enter the house first.

"I think it's one of the most cold-blooded acts that I ever came across in my experience as a police officer, for a father to send his boys in to do that," says Detective Standing.

Carolyn's son Daniel recalls the horrendous scene. "We went inside and heard a scream from the kitchen, so we all ran in. That's when we saw our mum in the kitchen. I believe Dad and Kenny had started doing CPR and we just got told to call the ambulance and go out the front, so then we spent the next 15 minutes or so waiting for the ambulance."

"I've still got sounds and stuff from the night that I can picture, that like makes me feel sick. It's not a nice thing to picture."

Kevin Matthews assumed the role of the grieving widower. He was a sobbing pallbearer at his wife’s funeral.

Play Video They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder. They’re Australia’s real-life black widows - greedy, ruthless women who prey on men, using sex to get what they want, manipulating their partners so completely they will even commit murder.

Kevin made a tearful public appeal begging for information about his wife’s murder. But the police were already closing in on her killers. Surveillance footage revealed Matthews meeting up with Michelle Burgess. But it wasn't the only proof they had of the relationship between the two.

"We actually had evidence from two people who saw them having sexual relations in a park in a public park," explains Detective Standing.

Both Kevin and Michelle told the police the same story - they had nothing to do with Carolyn’s murder, and denied the affair.

But the evidence against them was building, including a major clue left at the crime scene by their bumbling hitman David Key.

"The interesting thing that I saw there and always sticks in my mind is the shoe prints," says Detective Standing. "They were boot prints and very distinctive, and I thought, we get those boots and match them to whoever's done it, they've left behind some really nice evidence."

Finding a Cinderella match for the boots was made all the easier because Key couldn’t keep his mouth shut. He boasted about carrying out the hit. One of his confidantes was a former cellmate - Jason Colenso - and yet another of Michelle Burgess’ lovers.

David Key was finally arrested when the police pulled him over for speeding. He was wearing the same boots he’d used to kill Carolyn Matthews. Key confessed to the killing, telling police he’d destroyed the murder contract Michelle had drawn up by eating it in a sandwich.

But Key forgot to eat the other contract - the one ordering the hit on Michelle’s husband Darren.

Next, police arrested Michelle Burgess and charged her with Carolyn Matthew’s murder.

Kevin Matthews remained a free man. But even with the noose tightening, he couldn’t stay away from Michelle. He attended his lover’s first court appearance, wearing a hat with the word "forever" written on it. He mouthed words of support for her as she sat in the dock.

A month later, Kevin was charged with killing his wife.

"It’s disgusting what he did," says Detective Standing. "There was no need. All he had to do was divorce his wife. He killed her, deprived the boys of their mother when they really needed her young teenage boys. What he did was as low as you can go in my view."

In the end, the boys not only lost their mother, but their father as well.

"I don't have a father," says Carolyn's son Shane.

Michelle Burgess and Kevin Matthews received the longest sentences in South Australian legal history - 30 years each. David Key was jailed for 20 years.

Jail hasn’t mellowed Michelle Burgess. She continues to wield her lethal charm even behind bars.

"When she was locked up, she then started trying to have affairs with prison guards as well," explains Derek Pedley. "[It] lead to a rule that no male prison guard is to be left alone with Michelle Burgess. It's almost a reverse Hannibal Lecter-style situation. You can't leave a man alone with Michelle or she'll devour them."

Reporter: Michael Usher | Producers: Lisa Ryan & Rebecca Le Tourneau