Hannah Bonser was jailed for at least 22 years for murdering Casey Kearney in Doncaster, South Yorkshire, on Valentine's Day. Casey was going to a friend's house when Bonser – a stranger with a personality disorder – stabbed her with a kitchen knife.
Bonser, 26, had been in contact with agencies since 1993 when her GP raised concerns she was being neglected by her parents, an independent report said.
In January, she was offered crisis accommodation after telling mental health services she needed to be "locked up". She was later sent home.