The preliminary hearing for Andrew Delke, the Metro officer who shot and killed Daniel Hambrick, has been postponed three times, and has several questioning when the case will move forward.

Delke was charged with criminal homicide after the deadly shooting. Did he commit a crime, or was he simply doing his job? That's what will be decided.

The case is a first in the city's history -- an officer charged with such a crime for an act that happened while on duty.

Security camera video shows what happened on July 26 at the corners of 17th and Joe Johnson Boulevard in Nashville.

The affidavit said Hambrick had a gun. The video shows Delke square up and then shot him. It is part of what led the District Attorney to bring criminal charges

But will it be enough to get a Grand Jury indictment? Both sides talked about it back in September.

"Officer Dekle was protecting himself, his back-up officers who were on the way and the public," said David Raybin, Dekle's attorney in September.

Hambrick's mother Vickie countered, saying "For more than two months I have patiently waited for officer Delke to be charged with the murder of my son."

There are those who think the case is already set for trial, but the preliminary hearing must happen first. It's been postponed three times, and is now set for January 4.

The delay is likely from the prosecution and the defense asking for time to prepare for what is sure to be a contentious debate in court.

"At that hearing the judge will have to determine if there was probable cause that a crime was committed and that Mr. Delke may have been involved," said legal analyst Nick Leonardo.

Leonardo said there's no guarantee Delke will be indicted. The Grand Jury decides based on evidence at the hearing.

A long list witnesses are expected, and the jurors will also likely scrutinize enhanced versions of the security video.

Then they can decide not to indict Or to indict and then decide on what level of murder was committed.

"Is it first degree, second degree, manslaughter, reckless or criminally negligent homicide," said Leonardo.

Officer Delke is decommissioned, but still drawing his salary. His attorney said he will not consider any plea deal ... and will be prepared if and when this case goes to trial.

Delke remains free on bond. If he is indicted and the case is set for trial, it likely would not happen until at least late next year.