While Rosie Batty has called on people to learn the data on family violence, the statistics themselves often prove elusive.
In her Australia Day speech, Ms Batty cited the most reliable data we have, the Australian Bureau of Statistics' personal safety data, which says about one in six women have experienced violence at the hands of a current or former partner.
This 2012 data shows almost 17 per cent of women have experienced physical violence at the hands of a partner, while almost one in twenty have suffered sexual violence.
About five out of six of those who have been abused are no longer with their abuser, though the rest remain in their relationships.
And at the time of the survey, 1.5 per cent of women had experienced partner violence in the past 12 months. The rate was much higher for Indigenous women.
As Ms Batty pointed out, people are largely unaware of the statistics, although the statistics themselves could be improved.
Victoria Police themselves have admitted there have been gaps in their data collection and that they were previously understating the extent of the problem.
Homicides with a family violence component were not previously recorded as such and police have only recently gone back and reclassified a number of cases.
For example, 35 family violence homicides were committed in 2011-12, but only 30 were recorded as such that year. And these homicide stats do not just include murders but attempted murders, culpable driving causing death and aiding and abetting suicide.
But getting a concrete figure around the number of family violence deaths in Victoria each year is elusive due to differing definitions across departments and a lack of staff to compile the data.
Fairfax Media had requested data on victims of domestic violence but it appears Victoria Police's database was not equipped to carry out the query due to the way data was collated.
Meanwhile, Department of Justice reports on family violence have previously been presented in formats that were difficult to analyse.
Researchers have also spoken of the difficulties they face in using the existing data or in obtaining the information they require.
But there are signs of improvement.
The former Napthine government had identified the need for better statistics, and pledged $3.5 million to improve research and data collection in the lead-up to last year's election as part of its $150 million towards combating the family violence epidemic.
The Andrews government last year announced a royal commission into family violence, which is expected to look at data.
A new crime statistics agency in Victoria has also pledged to make crime statistics more available and accessible to the public.
The stats in Victoria – the ones that are publicly available at least – unequivocally show family violence is the biggest issue facing police.
It now accounts for more than half of the reported crime against the person, with 21,447 reports of assaults – nearly 60 a day – recorded last year. These assaults also include threats to kill or injure, which have become among the fastest growing offences of the past decade.
Another key front in the fight against family violence is intervention order beaches, which have now overtaken assaults for the first time, suggesting repeat offenders are taking up more and more police resources.
One in five people subject to an order in 2012-13 breached it, with 820 people – overwhelmingly men – breaching them at least three times.
Greg Anderson, Luke Batty's killer, had been subject of a family violence intervention order.
But the numbers do not necessarily mean family violence has become more prevalent. Police – particularly during Ken Lay's tenure as chief commissioner – have been urging more people to come forward. The effect might be that more people feel safe to report family violence, which can only be a positive sign despite the rising number of offences.
Nevertheless, better data would mean police could target resources more effectively, and could give researchers a better indication of the true extent of the problem.
