Violence needs fast punishment: US judge

A US judge says family violence perpetrators need to be punished as quickly as possible to show the issue is being taken seriously.

Fast sentencing is also important to keep victims safe and to prevent further offending, retired California Superior Court judge Eugene Hyman told the family violence royal commission in Melbourne.

"(Otherwise) the perpetrator's able to say to the victim `see, you made a complaint and nothing happened'," he said via video link.