Maria Stubbings, of Chelmsford in Essex, was strangled with a dog lead in 2008 by Marc Chivers, who had already killed a previous girlfriend.
Her brother Manuel Fernandez has told ITV Daybreak that the family have been calling for a public inquiry.
He said: "This highlights issues around domestic violence with one police force but it's actually a national problem."
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100-year-old tourist mugged by stranger after he fell getting off a bus as he returned to his Gloucester hometown with his 70-year-old son.
The case of a child killer who was the first person to be convicted under DNA evidence is to be reviewed by the Parole Board.
A summary of the day's election campaign stories in under one minute.