The girl shot by her estranged father in the head in Northiam on Thursday has died of her injuries.
Mary Shipstone was seven and lived in Spring Hill, Northiam, with her mother and brother.
She was shot shortly before 4pm on Thursday outside her home by a man in a car parked on a driveway next to her home.
She was taken to King’s College Hospital in London but died at 2.56pm on Friday, September 12.
A man also found dead at the scene but who has not yet been formally identified, is believed to be Mary’s estranged father, Yasser Alromisse.
He did not live at the address and was separated from Mary’s mother.
Yesterday Sussex Police confirmed that they were door knocking in Broomfield Avenue, Worthing, in connection with the incident.
Resident Michael Cloake, said: ““There is a permanent police presence. There were three cars last night and one on site all the time. We didn’t know the man but I think he lived a few doors down. He kept himself to himself. It’s a very quiet area and a friendly neighbourhood. It is a shocking and sad tale.”
Detective Chief Inspector Jason Taylor said: “This is a fast-moving investigation and there are still a large amount of inquiries being carried out before we can confirm the full picture of what happened.
“We are currently trying to establish Mr Alromisse’s movements over the last few days and are keen to hear from anyone who may have seen or heard from him.
“At this time however, I am not looking for anyone else in connection with this investigation and believe this to be an isolated incident.”
Chief Superintendent Neil Honnor, Sussex Police’s divisional commander for East Sussex, said: “This was a tragic domestic incident that has had the most terrible of outcomes for the family.
“We are working with partner agencies and local leaders to support and reassure the community who are understandably upset about what has happened.
“We are trying to be as open and honest with the public as we can but have to take into account the traumatic experience the family is going through as well as the fact that this is an ongoing investigation.
“If anyone has any concerns about the safety of their neighbourhood I would urge them to contact us but we are sure this was an isolated incident and that no one else is in any danger.”
Anyone with information about the incident should email email@example.com quoting Operation Oakfield, call 101 or contact the independent charity Crimestoppers anonymously on 0800 555111.
Mary’s family yesterday asked for a short statement to be released.
It reads: “We are today grieving the death of our beautiful and loving Mary.
“We would please ask that the public and media respect our privacy and allow us to try to come to terms with what has happened.
“We will not be making any further comment unless it is through Sussex Police.”