Sabina Nessa's housemate has revealed she began to panic when texts to her friend went unread, and has admitted "I don’t feel safe living here now".
The woman, who did not want to be named, told the Guardian: "I never thought something like this could happen to her.
“I had been texting her and it’s not like her to not reply to my messages.
“I don’t feel safe living here now."
Nessa, a 28-year-old primary school teacher from southeast London, left her home to meet a friend at around 8.30pm on 17 September.
The journey, through Cator Park in Kidbrooke, should have taken five minutes, but she never reached her destination.
Watch: Police release new CCTV footage looking for a second man in connection with Sabina Nessa's killing
Flowers have been left at the spot where Nessa's body was found, and a vigil has been planned for Friday evening.
Friends have said that they are now walking in groups to avoid being alone on the streets.
One told The Sun “I can’t believe what’s happened. It’s horrific. My heart is broken for her.
“Sabina was a beautiful woman - she had the whole world ahead of her.
“It’s so sad. She was so special. Her job was a huge part of her life. The school pupils were so special to her.
“We’re now walking in groups as a result of this. We’re not going out alone. I fear this will be a man who could strike again.
“I’m scared. We’re now keeping our movements shared with each other. We’re not going out alone.”
Sabina's death has sparked outrage after she joined a growing list of women killed in public spaces in London in recent months.
In March, Sarah Everard, a 33-year-old marketing executive, went missing after walking home from a friend’s flat.
Her remains were discovered a week later. Metropolitan Police officer Wayne Couzens, 48, was charged with her kidnap and murder.
Helen Anderson, 41 and mother of four from Finsbury Park, was found dead near the A3 in Guildford last month.
A 52-year-old man has been charged with her murder.
Maria Jane Rawlings, 45, was found dead in a bush in Romford 4 May, with a coroner ruling she had died from "neck compression."
A 20-year-old man has been charged with her murder.
Since Everard went missing 77 women have been murdered when a man is the principal subject, according to a report by ITV News.
It brings the total so far this year to 105, according to Counting Dead Women – a group that tracks femicide in the UK.
On Friday, detectives released footage of a man they want to speak to in the investigation into Nessa’s murder.
In the clip, the man can be seen looking over his shoulder and putting up his hood.
The CCTV revealed the mystery figure walking outside a block of flats in Pegler Square, in Kidbrooke, south-east London on the evening Nessa was attacked.
Metropolitan Police assistant commissioner Louisa Rolfe urged anyone who may know the man to contact them. Speaking outside New Scotland Yard she said: “Anybody out there who may know who he is, or if you’ve seen that footage, and you have any information, no matter how small, please do get in touch."
Police are continuing to question a 38-year-old man who was arrested on Thursday.
It has been claimed that Nessa's killer struck her on the head with an unknown object moments after she left her flat.
The attacker was seen putting the 28-year-old primary school teacher over his shoulder and carrying her towards Cator Park where her body was found nearly 24 hours later, the Telegraph reported, citing a police source.
Watch: 38-year-old man arrested on suspicion of Sabina Nessa's murder