The family of murdered Plymouth university lecturer Claire Chick has launched a petition in a bid to mandate category A prisons for murderers.
Paul Butler, 53, of Stangray Avenue, Plymouth, was jailed on 25 April for a minimum of 27 years for the murder of the 48-year old.
Ms Chick's daughter, Bethany Hancock-Baxter, said it was an "egregious oversight" that Butler had been placed in a category C prison following his crimes.
She said convicted murderers should start their sentences in category A prisons for "public safety" and "justice".
According to the Ministry of Justice (MoJ), prisoners are categorised based on a number of different factors and via robust risk assessment.
It said category C prisons were "training and resettlement" prisons, which offered the opportunity for inmates to develop skills in order for them to find work and resettle back into the community upon release.
However, it said high security category A prisons held male prisoners who, if they were to escape, pose the most threat to the public, the police or national security.
"Given the nature of their crimes, convicted murderers pose a significant threat to society and should therefore start their sentences in category A prisons," Ms Hancock-Baxter stated in the petition.
"This change is necessary not only for public safety but also as a measure of justice for the victims and their families who have suffered unimaginable loss."
The MoJ said it was unable to comment on the location of individual prisoners, but said "Mr Butler will remain behind bars for many years to come."
It said for guidance, the majority of male prisoners are held in category C prisons, adding a prisoner's categorisation was kept under regular review, and was based on a number of factors including a robust risk assessment.
Ms Chick was found seriously injured in West Hoe Road on the evening of 22 January and died later in hospital.
CCTV footage showed her being stabbed by Butler at least 23 times.
Judge Robert Linford at Plymouth Crown Court told Butler it was "nothing less than sheer murderous brutality".