Police statistics on domestic violence are not representative of society and are just bad statistics.

There is a lack of willingness for boys to report violence as it is embarrassing, as well as reluctance for police to press charges against girls.

Dominance and symmetry in partner violence by male and female university students in 32 nations
By Murray Straus [not a cop or a statistician, but an expert in Domestic Violence]

Prevalence that physically assaulted a dating partner (Table 1-Canada)

Minor Assault
Male 19.3%
Female 27.1%

Severe Assault
Male 6.6%
Female 9.5%

Female assault as percent of male = 140%