From London Tonight reporter Paul Brand:
For the past couple of hours police officers have been chatting to travellers at the site where the woman was killed last week.
We have been advised not to go onto the site but police confirmed that the woman's body was found in a field at the back of the camp.
A couple who run a riding school next door have been keen to make clear it was not one of their horses that was involved in the incident.
More top news
The 20-year-old was found fatally wounded on Roth Walk, near Finsbury Park, north London at around 3am on Saturday, Scotland Yard said.
Police have arrested a man wanted in connection with a burglary at the home of pensioner Richard Osborn-Brooks.
The rally comes after it emerged that the Home Office destroyed thousands of landing cards documenting the arrival of windrush-era migrants