A man found dead with his private school headteacher wife and seven-year-old daughter legally owned a gun that was discovered at the scene of the tragedy, police said.
George Pattison, 39, had been in contact with Surrey Police just days before the killings about his gun licence in order to change his address after the family moved to the school site from Caterham.
He was found dead with his wife Emma Pattison, 45, and their daughter Lettie at their home in the grounds of Epsom College in Surrey on Sunday.
Their deaths are being investigated as a possible murder-suicide.
We will be in close contact with Surrey Police over the coming weeks and months. We hope everyone will respect the privacy of Emma's family at this time and allow the College's pupils, staff and wider community the time and space necessary to come to terms with this loss. 3/3
— Epsom College (@EpsomCollegeUK) February 6, 2023
The Times reported that Mrs Pattison had contacted a close relative with concerns about her husband in the hours before the killings, and when they arrived at the house they found all three members of the family dead.
On Tuesday Surrey Police confirmed that officers have launched a homicide investigation.
While a gun was found at the scene the force said causes of death will not be confirmed until post-mortem examinations are carried out later this week.
A statement from the force said: “We had contact with George on Thursday February 2 after he notified us of a previous change of address, as is routine.
“Due to the short period of time between that contact and this incident, we have made a referral to the Independent Office for Police Conduct.”
The IOPC said it is assessing the information available to decide if any further action is necessary.
Detective Chief Inspector Kimball Edey, senior investigating officer on the case, said: “This is an incredibly traumatic incident and we are working around the clock to investigate and understand the exact circumstances which led to this point.
“We understand the public concern and upset, and we will clarify what we can, when we can, while respecting the right to a level of privacy for the families of those who have lost their lives.”
Mr Pattison had held a gun licence for a number of years and it was up for renewal early last year, according to the Times.
The newspaper said he had not been reported to Surrey Police before, but in 2016 had contacted them to allege that his wife had hit him, before withdrawing the claim.
Changes were made to gun licencing systems in the wake of shooting tragedies in Plymouth and West Sussex with new digital markers put in place to flag up to GPs relevant medical changes in patients with firearms licences.
In August 2021 Jake Davison killed his mother Maxine Davison, 51, three-year-old Sophie Martyn, her father, Lee, 43, Stephen Washington, 59, and Kate Shepherd, 66, in Keyham, Plymouth, just weeks after having his pump-action shotgun and certificate returned by police.
While in March 2020 Robert Needham, 42, killed his partner Kelly Fitzgibbons, 40, and two daughters Ava and Lexi Needham, four and two, before turning the gun on himself at their home in Woodmancote.