It is rare that police officers are tried and convicted on murder charges against civilians. Rarer still is the likelihood that a law-enforcement officer will face trial on the full strength of the charges a grand jury votes. It happens so often, it's become something of a professional courtesy.

That's why the case against four Minneapolis police officers who failed to stop a fellow officer from the torture-killing of a black man this past Monday must be monitored closely.

Leid Stories says a new body of laws needs to be developed, and current procedures eevised and strengthened, to protect against arbitrary excesses by officers of the law.