Police Commissioner Ray Kelly said it best: “This is all too familiar: police officers killed or put at grave risk by individuals who should not be on the street to begin with.”

Officer Alain Schaberger died Sunday morning after longtime thug George Villanueva allegedly pushed him over a Brooklyn brownstone railing during a domestic-violence incident, breaking the officer’s neck.

Sadly, the killing was predictable.

Villaneueva’s history of 30 arrests — including assault on a police officer, burglary and robbery — dates back 25 years. His rap sheet continued through most of the ’90s before he served a stretch in state prison in 1998.

Over the last year, he had multiple arrests for drugs and violations of a court order of protection — including one just last month. Sadly, the thug’s girlfriend declined to testify in the latter incidents.

Maybe some laws need to be updated.

Certainly, domestic-violence calls place cops at considerable risk — and the law needs to recognize that.

When a violent multiple offender like Villanueva violates an order of protection, requiring a police response, he needs to go behind bars — whether or not the “significant other” testifies.

He had repeatedly proven himself a menace — not just to his girlfriend, but to society itself.

Such a change in the law might have saved the life of Officer Alain Schaberger.