A St. Louis County grand jury is expected to review evidence related to the shooting death of Michael Brown, an unarmed 18-year-old, by Ferguson, Mo., police officer Darren Wilson. Here are some questions and answers about the process.

Q. What typically happens to Ferguson police officers when they are involved in a shooting that results in death of a civilian or fellow officer?

A. Officers in the department, and in departments throughout St. Louis County, are placed on paid administrative leave. They must also go to counseling before they can return to work. Authorities have said that Wilson is on paid administrative leave, but they have provided no additional information about him since the shooting.

Is a grand jury always consulted in the aftermath of such shootings?

Angry aftermath of the Missouri shooting

No. The St. Louis County prosecuting attorney reviews these cases, and if he believes the officer clearly acted in self-defense or did not violate any laws, the prosecutor may decide on his own to not file charges. But if there is any ambiguity about the circumstances of the shooting, the case must go to the grand jury.

Has a grand jury been empaneled for this case?

No. This is a standing grand jury, which serves a three-to four-month term and meets every Wednesday. The county prosecutor hopes to begin presenting evidence this Wednesday.

What will the grand jury assess in this case?

The county prosecutor will present evidence from the investigation of the shooting to the jury, which will determine whether Wilson should be indicted on any criminal charges, including homicide.

Will they be hearing from witnesses?

The county prosecutor has not said whether he will call witnesses. But legal experts say that it is likely and that the jury may eventually hear from Wilson. He may be considered a powerful witness — juries have a track record of wanting to believe police.

Will anyone represent Wilson?

Wilson is being represented by Gregory Kloeppel, a lawyer with the local Fraternal Order of Police, but grand juries do not normally hear directly from counsel for those whose actions are under review.

Will anyone represent the Brown’s family?

Brown’s family is represented by Benjamin Crump and Daryl Parks. The jury is exclusively looking at Wilson’s conduct to determine whether a criminal indictment is warranted, so they are unlikely to hear from those representing Brown’s family.

How long will the jury take?

The county prosecutor has not estimated the time it will take.

Why hasn’t Wilson been arrested?

The decision to arrest or not arrest Wilson now resides with the grand jury. If the jury decides to indict him, he will be arrested. Arrests typically occur at the time charges are filed or an indictment is issued, not during an investigation. A separate federal investigation, now underway, could also result in charges.

According to news reports, Wilson appears to not be at his home. Where is he?

Wilson’s location has not been disclosed by authorities. Authorities have said they are in touch with Wilson through his attorney and have no concerns about the officer fleeing.

Leonnig reported from St. Louis.