Miss Bernal was shot in front of shoppers
The gunman who murdered Harvey Nichols employee Clare Bernal at the store in west London had threatened to kill her, her ex-flatmate has told an inquest.
Nataliya Sarapionova said she was so worried about the behaviour of former security guard Michael Pech that she went to the store security manager.
Ms Bernal was shot several times by her former boyfriend at the store in 2005.
Ms Bernal's family, from Tunbridge Wells in Kent, had earlier called for stalking to be taken more seriously.
Ms Sarapionova said Pech had harassed and followed Ms Bernal after the pair broke up.
She said Pech made the death threat when Ms Bernal told him she would report him if he did not leave her alone.
"If you report me, I will kill you," Pech allegedly told Ms Bernal, according to Ms Sarapionova.
After shooting Ms Bernal on 13 September, the 30-year-old Slovakian shot himself dead in front of shoppers in the Knightsbridge store.
The store's security manager, Brian Lenehan, told the inquest he had been "deeply concerned" for Ms Bernal.
Mr Lenehan was worried enough to move Pech from Ms Bernal's floor and suggested she call the police immediately.
Mr Lenehan said the store launched an internal investigation, looking at text messages Pech had sent her after they broke up. They also interviewed some of Ms Bernal's friends.
The Westminster Coroner's Court was told the police did not take the evidence gathered by the store, but instead chose to mount their own investigation.
"At the time the only evidence the police had in their possession was Clare's say-so about it," Mr Lenehan said.
"We had information from several other members of staff which built a bigger picture. That might have caused them to have greater concern about it, I don't know."
The police defended their handling of the case saying Pech was considered "low risk" compared to other domestic violence cases.
"When I was speaking to Clare I was constantly making evaluations of the situation," Pc Bibi Shah, who dealt with the case, told the court.
"I assessed the risk as low in comparison to other crimes I was dealing with."
The inquest continues.