Stanford, California - A special prosecutor leading the grand jury may have been a better approach in the Ferguson police-civilian death case, a Stanford law professor says.

Robert Weisberg is an expert in criminal justice and serves as faculty co-director of the Stanford Criminal Justice Center. He talked with the Stanford News Service recently about the grand jury system in the wake of the civilian deaths at the hands of police in Ferguson, Mo., and New York City.

In the federal legal system, the grand jury is used to decide whether someone should be charged or indicted for a serious crime. The grand jury hears evidence presented by a prosecutor, and it can subpoena documents, physical evidence and witnesses to testify.

What works well in the grand jury system?

They work well when detailed and confidential investigations into possible crimes are needed. And where police searches, interrogations and voluntary interviews aren't sufficient, the subpoena power of the grand jury surely plays a pivotal role

What standard of evidence is used in grand jury proceedings? Is that different than trial juries?

A grand jury needs only find a "probable cause" to indict – that is a much lower threshold than "beyond a reasonable doubt."

Why trust in a secretive process like a grand jury? Shouldn't the entire American judicial process be open and transparent?

Secrecy may be useful in investigations. Even though witnesses can be forced to talk under subpoenas, the assurance of at least temporary secrecy may give them more incentive to speak openly. Secrecy also prevents untested allegations from going public and wrongly stigmatizing people.

England abolished their grand jury system two decades ago because of widespread belief that it did not work. Should that happen in America?

First, to abolish the grand jury, in at least the federal criminal system, would require a constitutional amendment, so don't hold your breath. It's true that the grand jury system usually rubber-stamps prosecutors, but it may sometimes provide a useful check – especially in very controversial cases, plus the investigative role remains.

Should the grand jury process have been used to investigate the police roles in the deaths of Michael Brown in Ferguson, Mo., and Eric Garner in New York City?

It's too soon to know what happened in regard to the grand jury deliberations in Staten Island (the Eric Garner case,) but in places where the prosecutor has discretion whether to proceed by grand jury – as opposed to a court filing followed by a preliminary hearing before a judge – prosecutors sometimes think the grand jury ensures a broad-based review of the evidence.

Sometimes in such cases, instead of the usual practice of just providing enough exculpatory evidence to establish probable cause, the prosecutor presents a fully neutral and balanced case, and then leaves things to the jurors. But in Ferguson, the prosecutor went a step further by essentially making a case against indictment. He was virtually admitting that he never wanted to go to the grand jury in the first place, and just thought he could not get away with that politically.

Is there a better way to investigate civilian deaths involving the police than through grand juries?

It would probably be better to have a grand jury scheme set up for such cases, perhaps with a special prosecutor, so the regular grand jury process doesn't get distorted.

Robert Weisberg, the Edwin E. Huddleson Jr. Professor of Law at Stanford University, recently wrote an op-ed on the grand jury issue for Stanford Lawyer. In the same publication, Stanford law professor David Sklansky also discussed what the federal government can and cannot do in the Brown and Garner cases.