text: Shana Grice, 19, was found with her throat cut in her bedroom at her Brighton home in August 2016.
  Her ex-boyfriend Michael Lane, 27, of Portslade, had placed a tracker device on her car, Lewes Crown Court heard.
  Miss Grice contacted police several times about Lane's unwanted attention before she died. The police watchdog has begun an investigation.
  A statement by her mother, Sharon Grice, read out in court by counsel, said: "We firmly believe her murder could have been avoided if her fears had been taken seriously by police.
  "Michael Lane had been harassing, stalking and pressurising her for over a year. Her life became a nightmare which we believe had affected her mental and physical health.
  "The brutal death of our daughter has ruined our lives forever. We have become mere shells of our former selves."
  Speaking after the verdict, Deputy Chief Constable of Sussex Police, Bernie O'Reilly, said the force had apologised to the Grice family.
  "When we looked at the circumstances leading to Shana's murder, we felt we may not have done the very best we could," he said.
  During the two-week trial, Lane admitted he had stalked Miss Grice and had lied to police in interviews, but denied murder.
  He had claimed he found her body and left her home without raising the alarm because he was in shock.
  But the jury returned its guilty verdict after just over two hours of deliberation.
  The court heard Lane refused to accept their break-up and was incensed when Miss Grice rekindled her relationship with ex-boyfriend Ashley Cooke, vowing to a friend: "She'll pay for what she's done."
  Prosecutor Philip Bennetts QC said: "During their relationship, he stalked her. He put a tracker on her car and followed her movements.
  "That obsession with her translated into killing her. He would not allow anyone else to be with her."
  Two days before Miss Grice was killed, she met Lane at a hotel in Hove to insist their relationship was over, but Lane claimed they had sex earlier that day.
  The evening before he killed her, he filled a red petrol can with fuel, but claimed he bought it to kill himself due to depression following his grandfather's death.
  The car mechanic waited until she was alone at the bungalow she shared with two housemates before cutting her throat and trying to set fire to her room.
  Prosecutors said one fire was started on the bed and another on the carpet, and Lane dismantled the smoke alarm in the hallway.
  After the killing, Lane withdrew Â£60 from Miss Grice's bank account and went to check a lottery ticket before he went to work at SE Tyres in Burgess Hill, where he was arrested.
  He is due to be sentenced on Thursday.
  Mr Justice Green warned Lane he faces a life sentence with a "very substantial minimum term".
  During the trial, the the court heard Miss Grice complained about her ex-boyfriend to police several times.
  The Independent Police Complaints Commission (IPCC) is conducting an investigation into the contact between Miss Grice, Mr Lane and Sussex Police in the lead-up to her death.
  Mr O'Reilly said: "Within days of her murder I personally visited Shana's family to apologise on behalf of Sussex Police and we made a referral to the IPCC.
  "We have thoroughly reviewed all aspects of how we deal with cases of stalking and harassment and we have now taken on the learning and our approach is more robust."
  An IPCC spokesman said investigators had already interviewed a number of witnesses and further interviews would be carried out now the trial had finished.
target: A man who stalked and killed his former girlfriend after she rejected him has been found guilty of her murder.