Serial Killer Joanna Dennehy Ruthlessly Murdered 3 Men — Now Her Daughter Speaks Out

It’s said the apple doesn’t fall far from the tree — meaning a person is typically not that different from their parents.

But Shianne Treanor, the 21-year-old daughter of the notorious serial killer Joanna Dennehy, who’s now serving a life sentence for killing three men and injuring two others, says that there are exceptions. She’s one of them.

“I’m not her,” she declared in “Living With a Serial Killer,” premiering Wednesday, April 14 at 9/8c on Oxygen. “I’ll never be her.”

In March 2013, Dennehy’s deadly spree came to light with the discovery of the body of property manager Kevin Lee, 48, in Peterborough, 100 miles north of London. A day earlier his wife had reported him missing, along with the family’s blue station wagon.

Kevin Lee

Lee’s vehicle, which had been torched, was located five miles from where a dog walker stumbled upon Lee’s dead body in a ditch. Lee had been stabbed five times, was dressed in a woman’s cocktail dress, and appeared to have been sexually assaulted.

The investigation quickly led to one of Lee’s associates, Gary Stretch, 46, who was captured in a gas station security video with Lee’s car. Stretch was with a woman identified as Dennehy, 36, one of Lee’s tenants.

Related: Former Cecil Hotel manager reflects on death of Elisa Lam

As investigators searched for Stretch and Dennehy, police learned that two more men had been stabbed multiple times while walking their dogs 140 miles away in Hereford. The victims, Robin Bereza, 63, and John Rogers, 56, survived their wounds. One told investigators that the attacker was a woman with a star tattoo on her face. Dennehy was known as Star, thanks to a tattoo on her cheek.

Witnesses to the vicious attacks on the dog walkers told authorities that Dennehy walked away from the scene laughing and licking her knife, according to “Living With a Serial Killer.”

Gary Stretch and Joanna Dennehy

Dennehy and Stretch were soon apprehended and taken into custody.

At the time, Treanor hadn’t laid eyes on her mom in four years. She told producers she wondered, “Why is she not here? Why am I not good enough?”

Her mother’s arrest spawned feelings of fear, anger, and distress.

“I cried so hard I had nothing left to cry ... I lost all my senses and fell to the floor crying,” said Treanor. “The first thing I said was, ‘Will I turn into her? Will that be me?’”

Treanor also acknowledged that even as a girl she knew her mom was provocative as well as slyly manipulative with men.

Shianne Treanor

After Dennehy’s arrest, she was immediately sent for a mental health assessment that made it impossible for police to interview her for 10 days. They used that time to dive deeper into Dennehy’s background and uncovered that she had a sexual relationship with Lee.

As this line of investigation continued, they also learned that the bodies of two men were discovered in a ditch five miles from where Lee was found. The homicides became known as the Peterborough ditch murders.

Using fingerprints, detectives identified the victims as delivery man Lukasz Slaboszewski, 31, and John Chapman, 56, a down-and-out widower who lived in one of Lee’s houses. Police established that they had been killed days before Lee.

John Chapman

An anonymous witness soon came forward and told officials that Dennehy had bragged to her about slaughtering these victims. She had stabbed Slaboszewski in the heart and disposed of him with Stretch’s help, and butchered Chapman in his sleep.

Investigators learned that Stretch and Dennehy, who compared their acts to Bonnie and Clyde, used a stolen camera to chronicle their crime spree. In one unsettling picture, Dennehy holds a giant dagger and sticks out her tongue as if to lick the blade.

Joanna Dennehy

On April 12, investigators got the OK to finally interview Dennehy, who’d been diagnosed with the disorder paraphilia sadomasochism. When asked about the stabbings, she responded, “No comment.”

Despite her silence, police had already built a strong case against her. Authorities’ main concern was that Dennehy would plead insanity. Instead, on November 18, 2013, she shocked everyone, including her own legal team, by pleading guilty to three murders and two attempted murders.

It was her way of securing even more notoriety and taking control, criminologist Dr. Casey Jordan told “Living With a Serial Killer.”

Stretch, however, had pleaded not guilty. His trial went on as scheduled. It came out during his trial that after Dennehy killed Chapman she allegedly borrowed a line from a Britney Spears hit song and said, “Oops, I’ve done it again.”

Lukasz Slaboszewski

In February 2014 Stretch was sentenced to 19 years for his role in the crimes. Dennehy — like Britain’s other two infamous female serial killers Myra Hindley and Rosemary West — was sentenced to life in prison.

In 2018, despite people’s efforts to discourage her, Treanor visited her mother in prison. “She doesn’t feel remorse for what she’s done,” said Treanor, who subsequently made the decision to cut off all communication with Dennehy. “She’s past the point of change.”

To learn more about the case, watch “Living With a Serial Killer,” premiering Wednesday, April 14 at 9/8c on Oxygen or stream episodes here.