The husband of Epsom College's headteacher appeared introverted and "older than his years", according to a former neighbour.
George Pattison, 39, was found dead with his wife Emma, 45, and their seven-year-old daughter Lettie at their home in the grounds of the school in Surrey on Sunday.
On Tuesday, police confirmed they had launched a homicide investigation, and said Mr Pattison legally owned a gun that was discovered at the scene.
The deaths are being investigated as a possible murder-suicide, where Mr Pattison killed his wife and daughter before turning the gun on himself.
The tragedy is believed to have taken place just three weeks after he moved into their new house, which he had been "flitting between" while a sale went through on the couple's former home in Caterham.
A former neighbour told MailOnline:"I think he may have worked at home a bit but I got the impression he had a lot of time on his hands.
"I'd see him through the window drinking glasses of red wine in his new kitchen extension."
He "seemed older than 39, and looked and acted like someone approaching 50 not 40", they added.
Mr Pattison was a chartered accountant who was director of a management consultancy called Tanglewood 2016, according to Companies House.
Accounts for the year ending October 2021 show he had taken out a £14,076 director's loan.
It comes after reports that Mrs Pattison had contacted her sister with concerns about her husband in the hours before the killings, and when she arrived at the house she found all three members of the family dead.
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.
Mr Pattison 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.
A statement from the force said: "We had contact with George on 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.
Mrs Pattison became Epsom's first female head in September 2022 after six years as headteacher of Croydon High School in south London.
Boarding students at the college pay more than £42,000 a year and its alumni include Conservative MP Sir Michael Fallon, broadcaster Jeremy Vine and comedian Tim Vine.
