- Video report by ITV News reporter Sally Lockwood
The mother of a young woman who was murdered by her obsessed ex-boyfriend has spoken of the immense "guilt" she feels for not realising the danger her daughter was in.
Alice Ruggles' former boyfriend stalked then murdered her by slashing her neck from ear to ear.
On Wednesday, Lance Corporal Trimaan "Harry" Dhillon was jailed for life with a minimum term of 22 years for the act of "utter barbarism".
The 26-year-old had driven 120 miles from his barracks near Edinburgh to confront Ms Ruggles.
Dhillon broke into her Gateshead flat in October 2016 and slit her throat with a carving knife after finding out she had a new boyfriend.
Ms Ruggles' mother, Dr Sue Hills, told how she "felt a sense of guilt" for telling her daughter "not to worry" as she thought the concerns of Ms Ruggles and her sister, Emma, were an "overreaction", and that "that stuff didn't happen".
Dhillon - who had repeatedly cheated on Ms Ruggles during their relationship - left the 24-year-old terrified after they split up, knocking on her door at night, tapping on her window and leaving flowers and chocolates on the sill.
The soldier's actions led Ms Ruggles to complain to the police and gain an official PIN warning, telling him to leave her alone, which he ignored.
Dhillon also tried to hack Ms Ruggles' social media accounts and messaged her new boyfriend, trying to make out the she was two-timing him.
Speaking after Wednesday's sentencing, Dr Hills said she had "failed" her daughter by teaching her to see the good in everyone, and also by not standing up to Dhillon herself after he contacted her on Facebook.
"This feeling of failure will stay with me forever," she said, adding she would never forgive herself for advising her daughter that if she ignored Dhillon, he would eventually stop contacting her.
Ms Ruggles' father, Clive, added: "We all share a sense of guilt. Rationally we know only one person is responsible.
"All of us feel we should have paid more attention to aspects of his personality that perhaps should have forewarned us."
Dr Hills recalled Alice phoning her with concerns about her former boyfriend just two days before he killed her.
"It was really horrendous because only two days before I had been talking to Alice on the phone and she told me about the whole thing," Dr Hills said.
She continued how her daughter told her about "the second call to the police, and I sort of reassured her that it was ok, the police knew what was going on and that it would be alright.
"Emma rang up and said 'Mum, you cannot tell that to her, he's going to kill her, you've got to do something. I'm thinking of having time off work to go and stay with her'.
"I thought she was overreacting, so I just said 'don't be silly, Don't do that'.
"I just sort of thought that stuff didn't happen, and so of course as soon as I saw the police I knew, so I felt a sense of guilt for having, first of all told Alice not to worry, and secondly told Emma not to be silly, when actually if I hadn't said that Alice might still be alive."
Ms Ruggles' family are now calling for better police training on how to deal with stalkers, saying they want their daughter's legacy to save the lives of other women and girls.