The shop assistant shot dead in Harvey Nichols by her ex-boyfriend after months of intimidation, was failed by the system, say campaigners.
Michael Pech had threatened to kill Clare Bernal, 22, from Tunbridge Wells, and was due in court next week for sentencing after admitting harassment.
But he shot her in the head at the exclusive London store on Tuesday, before killing himself.
Domestic violence charity Refuge said he should never have been given bail.
The charity wants tougher guidelines and compulsory risk assessment training for judges and magistrates.
Refuge chief executive, Sandra Horley, said: "Clare Bernal did all that she could to stay safe but the system failed her.
'High risk case'
"Mr Pech was brought before the courts on two separate occasions.
"He had a history of domestic violence and had threatened to kill Clare. He had even admitted his crimes to the court.
"Clearly this was a high risk case and the courts should have taken it more seriously. This was a tragic loss of life which may well have been prevented had the court recognised the risks and denied bail."
Former Harvey Nichols security guard Pech, 30, had a brief relationship with Ms Bernal, but after it ended he is said to have pestered her with phone calls and started following her.
One colleague, Meilan Baxter-Cockbill, claimed that when Miss Bernal made clear she was not interested in taking him back, Pech told her: "If I can't have you, nobody will."
Pech, who had threatened to kill Miss Bernal in March, had been on bail on the condition he did not contact her or go to Dulwich Village, south-east London, where she lived.
On Tuesday evening, he walked into Harvey Nichols in Knightsbridge and shot her several times in the head, before turning the gun on himself.
Ms Bernal's mother Tricia described her daughter as someone who saw "the good in everyone".
Friends from Tunbridge Wells in Kent, where she went to school, paid tribute to her on Thursday.
At her old school, St Gregory's Catholic Comprehensive, headteacher Rosemary Olivier said she was remembered with affection as a "gentle and shy student who was kind and thoughtful".