Their bodies were found at their home on the grounds of Epsom College, where Mrs Pattison was head teacher.
George Pattison shot his wife and their seven-year-old daughter, Lettie, in February last year
An allegation of assault made by Pattison in 2016 was “clearly part” of his controlling behaviour, police have now said.
They did not identify any abuse by Mr Pattison at the time and no action was taken due to a lack of evidence.
Ch Supt Davies said the deaths highlighted the need to dispel the myths of who may or may not be a victim of domestic abuse.
