A man with a history of violence against former partners has been jailed for life for murdering his fiancee.

Jack Johns, 53, killed 51-year-old Malgorzata Wiktor, also known as Gosia, six months into their relationship after “love bombing” her when they met, Leeds Crown Court heard.

Gosia and her friends and family had raised concerns about Johns’s “intense” behaviour in the days and weeks before her death on 11 June this year.

Sentencing the defendant to a minimum of 29 years in prison, Judge Tom Bayliss KC described him as an “obsessive, possessive, domineering and unstable individual”, telling him: “You are, Jack Johns, an extremely dangerous man.”

The judge said there were “classic markers of coercing and controlling behaviour” in Gosia’s relationship with Johns, who pleaded guilty to murder in September.

Her friends and family had used the terms “overwhelming” and “love bombing” to describe his initial behaviour towards her, according to prosecutor Geraldine Kelly KC.

“In the last week or so before he killed her, she too had raised concerns with her cousin about over-the-top behaviour and over-the-top affection.”

Gosia, who lived in the Belle Isle area of Leeds after moving to the UK with her son Gracjan from Poland about 20 years ago, had complained of feeling “suffocated” in the relationship.

The mother-of-one said Johns, of School Street in Tingley, was “too intense […] watching her when she was sending texts to other people, overly emotional [and] too clingy”.

The pair were engaged within three months, which Gosia, who worked as a receptionist at a dental practice, said “felt rushed and that [Johns] was putting pressure on her”, Kelly told the court.

By May, Gosia had “begun to fear” her fiancee, Kelly said.

A colleague who described her as “loud and vibrant” before the relationship said she had become “quiet and sad”.

The day before her death, Gosia had sent a voice note complaining that Johns “wasn’t sharing his past”.

On 11 June police were called to her home address after colleagues had raised the alarm with Gracjan when she did not arrive for work.

Gosia was pronounced dead at the scene having suffered multiple skull fractures and stab wounds, the court was told.

In a victim impact statement, Gracjan said his mother was “the kindest, most loving and trusting person I have ever known”, adding: “Everyone who had the priviledge of knowing her loved her.

“The most difficult part is that mum was taken away without warning and without the opportunity to say goodbye.”

Gosia’s sister, Anna, said: “Something died in every one of us that day.

“He [Johns] destroyed our family’s world.

“The consequences of this crime did not end on the day that Gosia died.”

Monday’s sentencing hearing was told Johns had changed his name from Colin French after being convicted of offences against two previous partners, in 2006 and 2016, in other parts of the country.

The defendant was given an Imprisonment for Public Protection (IPP) sentence for the 2006 offence of arson endangering life, when he set fire to the home of his ex-girlfriend while she and her family were inside.

Ten years later, he attempted to kidnap another woman he had been in a relationship with after hiding in the boot of her car.

The court heard the defendant’s period spent on licence – aimed at protecting the public and preventing reoffending – for the latter offence ended in 2024.

Judge Bayliss told the court there were a “number of strikingly similar circumstances” in the offences.

He said: “It’s unfortunate to say the least that an extremely dangerous man was in a position, under a new name, to start a relationship with this poor woman.”

The court heard Johns had refused to discuss the circumstances of Gosia’s death, which Judge Bayliss said was “the culmination of a campaign of coercive and controlling behaviour”.

“The murder represented the final assertion of control.”

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