(CNN) -

Was a police officer justified in shooting and killing Michael Brown?

That's the question at the heart of the looming legal battles over the controversial case.

What charges could Ferguson Police Officer Darren Wilson face? What would state and federal authorities have to prove in order to pursue charges? And does the fact that the gunman was a police officer change how the case could play out?

Here's a look at what legal analysts say could happen next.

Was a state crime committed?

A local grand jury has started hearing testimony, but that doesn't mean any particular charges are being recommended by prosecutors at this point, CNN senior legal analyst Jeffrey Toobin said.

"An investigation is just an investigation. ... It's just something that they're looking into," Toobin said.

For a criminal case to go forward, the grand jury must decide whether a crime was committed, and whether it's more likely than not that the accused person -- in this case, Wilson -- committed the crime, said CNN legal analyst Sunny Hostin, a former federal prosecutor.

After a fatal shooting, a range of charges are typically on the table, said CNN legal analyst Danny Cevallos, a criminal defense attorney. "They're going to be anything in the spectrum of murder, manslaughter (or) negligent homicide," he said.

The prosecutor will make a recommendation to the grand jury.

From there, the grand jury could decide to indict Wilson, or that there isn't enough evidence to move forward. In order to bring charges against Wilson, nine of 12 jurors will have to agree.

But the prosecutor plays a key role in the hearings, which are not open to the public.

"The grand jury ultimately decides whether to indict, but it's 100% the prosecution's show. ... The prosecutor could, in theory, make less of an effort if he doesn't want someone indicted," Cevallos said.

Some residents and community leaders contend St. Louis County Prosecuting Attorney Robert McCulloch has deep ties to the police and has favored law enforcement in criminal cases.

J.Tom Morgan, a former district attorney in Georgia who knows McCulloch, defended him as fair and objective.

"I believe Mr. McCulloch will present the facts and the evidence to the grand jury and the Missouri law as he is required to do so," Morgan said. "We do not put defendants on trial just to see what a jury will do."

Were Brown's civil rights violated?

As part of a federal civil rights investigation, authorities are interviewing witnesses and weighing a number of factors.

Key among them: whether Wilson exhibited "racial hostility," Toobin said.

"The most important thing would be, did he say anything that indicates racial hostility, either before, or after, or during (the shooting)?" Toobin said.

Wilson is white, and Brown was African-American.

"The bar is very high," Hostin said, "and they're difficult cases to prove."

But race doesn't have to be a factor in the shooting for investigators to allege there was a federal civil rights violation, Cevallos said.

Federal statute says it's a crime for government officials "to willfully deprive a person of a right or privilege protected by the Constitution."

Federal prosecutors could argue that Brown's right to life was violated, Cevallos said, but it's a tough case to make.