The Duchess of Cambridge has written a "deeply personal and heartfelt letter" to Sarah Everard's family, according to reports.
Kate expressed her sadness and sympathy to the 33-year-old's loved ones in the message, according to the Daily Mirror.
Ms Everard went missing on 3 March while walking home from a friend's house in south London, and her body was found in woodland near Ashford in Kent a week later.
The duchess was among those who visited a memorial for Ms Everard at Clapham Common two weeks ago - not far from where she went missing.
It is understood Kate made the visit in part because she remembers what it felt like to walk around London at night before she got married.
She was seen pausing in front of floral tributes to Ms Everard, which were placed around a bandstand in the south London park.
According to the newspaper, Kate wrote the letter because she felt it was important for her to pay her respects personally.
It quoted a source saying: "Kate's letter was deeply personal and heartfelt, she expressed her absolute sadness at what Sarah's family and loved ones are going through.
"She said she knows that no words can change what happened but that she wanted to let them know that they and Sarah are in her thoughts."
Kensington Palace said it would not comment on private correspondence.
Serving police officer Wayne Couzens, 48, from Deal, Kent, has been charged with murdering Ms Everard.