Missouri law could protect Ferguson Officer Darren Wilson

Saturday marked two weeks since unarmed Missouri teen Michael Brown was shot and killed by police officer Darren Wilson.

"We're hurt," Brown's father told KSHB. "There's no telling what he's doing. He has his life, but our son is gone."

Many protesters insist they won't stop demonstrating until Wilson is arrested.

"I think the first thing that needs to happen, you need to arrest Officer Wilson. He shot and killed a man, shot him multiple times." Harvard Law School Professor Charles Ogletree told NBC. "No one knows anything about him, no one knows why he did it."

So why hasn't Darren Wilson been arrested? As The Christian Science Monitor points out, not everyone agrees that Wilson should be taken into custody. That divide can even been seen among law professors within the same university.

The Monitor quotes another Harvard law professor who says, "We should not arrest [Officer Darren Wilson] until there's a substantial level of proof of criminality, even if it appeared that the police acted improperly."

But opinions aside, there are also some practical obstacles to moving ahead with any prosecution of Wilson.

Missouri's Defense of Justification statute gives police officers broad authority to use deadly force in cases when, "He or she reasonably believes that such deadly force is necessary to protect himself, when he reasonably believes that such use of deadly force is immediately necessary to effect the arrest" and when the subject "May otherwise endanger life or inflict serious physical injury unless arrested without delay."

It's the same law that was invoked in 2000 after two unarmed men were shot and killed by police at a Berkeley, Mo., Jack in the Box.

At the time, Ferguson's police chief, Tom Jackson, was deputy commander in Berkeley.

During that investigation, Jackson defended his officers, who claimed the men in the car had started toward the police vehicle in an effort to escape and the officers feared for their lives.

According to The Daily Beast, investigators in that case found the car had not begun to move towards the officers when the fatal shots were fired. However, the officers were ultimately able to justify their actions under Missouri law by claiming they were in fear for their lives at that moment because the car was a deadly weapon pointed in their direction.

If Wilson is charged in Brown's death, his attorneys could invoke the Missouri law by simply arguing that he believed Brown posed a serious threat to his life, as Business Insider points out.

Wilson's supporters also play a large role - pointing to witness accounts that Brown was the aggressor in the situation, and the police union says it's just too soon for judgment when there's no clear picture of what actually happened Aug. 9.

Wilson's supporters have also started fundraising campaigns for the officer, including a GoFundMe page that has raised more than $230,000. And two Facebook pages in support of Wilson have almost 100,000 likes combined.

The jury in this case began hearing evidence earlier in the week, but as CNN notes, the process is far from over.

"It may be until mid-October before the panel gets through all of the evidence," CNN reports. "That's so important to see as much evidence as they can. So if this officer ... is charged, it may not happen until then."

Until then, a writer for Salon notes the prosecution has two choices: the first, "immediately press charges, issue a warrant for the officer's arrest and arrest Officer Wilson." Or it could hold back, then "present the case to a grand jury and see if the grand jury will find probable cause to indict the officer." Regardless of whether Wilson is soon arrested, the grand jury would still have to find probable cause before he would be indicted.

Michael Brown's funeral is scheduled for Monday.