Inside how brutal serial killer John Sweeney was finally caught after six years on the run

The ITV series, Until I Kill You, continues this week and is based on Delia Balmer's memoir, Living With A Serial Killer. It tells the chilling tale of how John Sweeney, initially a caring partner, gradually turned aggressive and controlling.

Sweeney trapped Delia in her own home multiple times, torturing her and even confessing to the murder of his ex-girlfriend, Melissa Halstead. After a final violent episode that nearly claimed Delia's life, Sweeney fled.

Incredibly, it took the police six years to locate him and convict him for several murders. Prior to the brutal attack outside Delia's residence, Sweeney had already had run-ins with the law due to a previous assault on her.

Despite this, he violated police conditions by visiting Delia's house and assaulting her with an axe and knife, causing her severe, life-altering injuries. Following the 1994 attack, he evaded capture for six years before being apprehended at a building site in central London.

Before returning to London under a false name, he had killed another woman, Paula Fields. Police were eventually able to link him to both murders through a collection of unsettling drawings and poems, reports the Mirror.

Over 300 pieces of artwork were discovered, including one titled the Scalp Hunter, which portrayed a female victim and a bloody axe.

On a discarded scratchcard, he had scrawled a chilling verse about his first girlfriend, also the victim of his murderous spree. The grim words found were: "Poor old Melissa, chopped her up in bits, food to feed the fish, Am*dam was the pits."

The dismembered remnants of Melissa were discovered in the Westersingel Canal in Rotterdam after she disappeared from her flat in Amsterdam back in 1990.

It wasn't until 2008 that she was finally identified when tenacious Dutch detectives re-examined the cold case and secured a match using familial DNA.

The reinvestigation of this harrowing case was given new momentum partly due to financial support from the European Union.

Sweeney's second known victim, Paula Fields, who hailed from Liverpool, came into his life in 2000.

Merely three months after their paths crossed, Paula went missing, and subsequently, parts of her body were unearthed in six bags in Regent's Canal near King's Cross in February 2001.

After an enduring manhunt, Sweeney was apprehended in 2007, a full six years following the grim find of Paula's dismembered body.

It was Sweeney's own macabre collection of art that ultimately implicated him in these heinous acts and tied him to both murders.

Within one haunting piece, named One Man Band, lay the image of a woman, likely Melissa. Tellingly, a patch had been obscured with correction fluid.

Under ultraviolet scrutiny, this hidden section betrayed a tombstone marked with the epitaph "Melissa Halstead, born 7 November 1956. Died."

Until I Kill You continues on ITV at 9pm