The authorities has been urged to property up with plans to unit criminals to be their ain sentencing hearings.
Thomas Cashman refused to participate the dock erstwhile helium was jailed for astatine slightest 42 years connected Monday for the shooting execution of Olivia Pratt-Korbel successful her ain home.
The aunt of different execution unfortunate called connected Justice Secretary Dominic Raab to expedite plans to compel criminals to look for sentencing.
Farah Naz besides wants judges to person the quality to punish those who refuse.
The Ministry of Justice has been approached for a response.
Opposition Leader Sir Keir Starmer said due to the fact that Olivia's household "couldn't hide" from Cashman's "horrendous crimes... helium shouldn't beryllium allowed to" either.
Ms Naz's niece Zara Aleena was sexually assaulted and murdered by Jordan McSweeney aft helium attacked the 35-year-old instrumentality postgraduate portion walking location from a nighttime retired successful Ilford, Essex, connected 26 June.
Like Cashman, helium besides refused to be his sentencing successful person, starring Ms Naz to accidental helium had wrongly taken power of the courtroom.
She said: "It's the past spot of powerfulness that needs to beryllium taken distant [from offenders].
"I deliberation determination are different ways to marque the convict travel to look their judgement and that would beryllium to adhd clip to their sentencing, oregon determination tin beryllium different ways.
"Otherwise we don't person radical deterred from committing crimes - if they're conscionable moving from compartment to compartment there's nary consciousness of punishment.
"I would similar Dominic Raab to determination guardant with processing this law."
Ms Naz said she felt "really sad" for Olivia's household that they were not capable to spot the antheral who "destroyed their lives" being sentenced.
"Surely the judgement is portion of the punishment," she asked.
"We each wanted to look him erstwhile we were speechmaking retired unfortunate interaction statements.
"We wanted to ticker him ticker the footage of his murdering Zara - what helium did to her," she said.
"As a effect the full ineligible process felt incomplete.
"He took powerfulness implicit Zara and then... successful the courtroom helium took power. It felt similar helium was capable to person that," she said.
"Surely erstwhile they person been convicted... each their rights are removed?"
Cashman, 34, killed Olivia and injured her parent Cheryl Korbel arsenic helium chased a chap cause trader into their Dovecot location connected 22 August.
Neither Cashman nor his intended people Joseph Nee were known to Ms Korbel.
Sentencing him successful absentia astatine Manchester Crown Court, Mrs Justice Amanda Yip said cause trader Cashman's refusal to look successful tribunal was "disrespectful" to Olivia's family.
She said helium was "not of erstwhile bully character", had made it wide helium was a criminal, and had "demonstrated nary remorse".
"His nonaccomplishment to travel into tribunal is further grounds of that," she said.
Commenting connected Cashman's refusal to participate the dock, a Ministry of Justice root said Olivia and her household "weren't capable to fell from Thomas Cashman's crime, truthful helium shouldn't beryllium capable to fell from justice".
The root said: "This is precisely wherefore the Deputy Prime Minister [Dominic Raab] is committed to changing the instrumentality truthful that offenders are forced to look the consequences of their actions."
Following McSweeney's sentencing, Mr Raab said successful February helium was examining whether judges should beryllium capable to enforce longer presumption connected those who refused to travel to court.
Labour person Sir Keir added: "For immoderate clip we person been saying determination needs to beryllium a alteration successful the instrumentality to halt this.
"For galore victims and their families determination is this consciousness of a spread successful the process if the suspect doesn't really travel and look justice. Of people it is cowardly.
"One of the ideas would beryllium to let the justice to person the powerfulness to summation the condemnation if the suspect didn't travel into tribunal to look justice.
"We should look astatine each options - we request thing that works."
He added: "At the infinitesimal determination is that profound consciousness of a spread for victims and their families and we request to bash thing astir that.
"We person been calling for this for immoderate clip now. The authorities says it is funny successful that."
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