A legal look: Reasonable force or police brutality against Mike Brown?

In the five days since a police officer gunned down an unarmed college-bound black teenager returning from a convenience store, unrest continues to engulf Ferguson, a predominantly African-American suburb of St. Louis.

One of the legal questions being raised: Was the shooting by police officer Darren Wilson an illegal act or reasonable force?

Coming on the heels of other high-profile cases of unarmed black men being shot or killed – from the 2012 shooting of Trayvon Martin by a neighborhood watch volunteer to the July chokehold death of Eric Garner by a New York police officer – news of 18-year-old Michael Brown’s death in Ferguson, Mo., on Saturday raise anew questions about excessive police force.

"It’s hard to imagine what would justify multiple gunshots at an individual going away from the police who’s unarmed," says Peter Joy a law professor at Washington University Law School in St. Louis.

Professor Joy is referring to two eyewitness accounts of the shooting. Proving in a court of law what happened to Michael Brown may be difficult because as of yet no videos or photographs have been released publicly. Investigators will need to contact each witness and painstakingly reconstruct everyone’s movements, says Cornell University law professor Jens David Ohlin. This reconstruction will need to answer such questions as “where was the police officer standing, where was the victim standing, how was he moving his arms, when the shots were fired, was the victim standing still or moving in any particular way.”

Unlike the 2012 Trayvon Martin trial – which involved a Florida civilian’s use of force in a what was successfully argued as a self-defense scenario – Brown’s death may more closely resemble the legal issues in the New York Police Department chokehold incident, based on the facts known so far.

The Ferguson and New York City cases each involve the police use of force, which is governed by a relatively clear legal standard  – that an officer may shoot if he has probable cause to believe that the suspect poses a grave or mortal threat to one’s self, public, or the officer.

It may be hard to argue that Eric Garner posed a grave threat to anyone, especially since the NYPD regulations "prohibit the use of a chokehold because you can accidentally cause death," says Professor Ohlin. By contrast, in Michael Brown’s death, it is not yet known if Officer Warren violated the legal standard of excessive force.

Police may justify the use of deadly force – even if an individual is unarmed – based on the Supreme Court’s 2007 ruling in Scott v. Harris, in which the justices stated that it is appropriate for a police cruiser to ram into a fleeing suspect's car since his speeding threatened others.

"A police officer's attempt to terminate a dangerous high-speed car chase that threatens the lives of innocent bystanders does not violate the Fourth Amendment, even when it places the fleeing motorist at risk of serious injury or death," wrote Justice Antonin Scalia in the majority opinion.

But given the known facts in Ferguson case, it would be difficult for the police to argue that Michael Brown's flight on foot posed a risk to bystanders.

Even if a court were to find that the Ferguson police officer used excessive force, he could still be found "not guilty" due to the high hurdles in wrongful death cases against police – as in the 1991 Rodney King beating which sparked riots in Los Angeles.

If a police officer’s actions don’t meet the higher legal standard – which include questions such as did the officer exercise self-defense or feel threatened enough to respond with deadly force – the cop or the police department could face a civil lawsuit for violating the victim’s civil rights.

Given the lack of information and the early stages of the investigation – being conducted by the St. Louis County Police Department, the FBI and the Justice Department’s Civil Rights division – it's not clear yet whether charges will be filed against Officer Warren for shooting Michael Brown.

"The law on excessive force gives a lot of deference to the police officer and his objective view whether he was facing a threat," says Joy. "Given that and that close relationship between the prosecutor and police officers, quite often at the state level, the likelihood of prosecution is very slim in many instances."

When these types of shootings occur, the suspected officer speaks with a police union assistant and a lawyer before giving his account to anyone, says Joy, as the investigating police won’t even question the officer until he has retained counsel.

If the investigations culminated in criminal charges, Ohlin said they would probably be some form of reckless homicide, which can be either second-degree murder or manslaughter.

Whether criminal charges are filed or not, Brown’s family will likely file a civil suit for financial damages, adds Ohlin.

Incidents of excessive use of police force aren't happening more often than in the past, but social media magnifies the incident by turning a local story into a national saga, says Joy. "Now, the general public throughout the country is much more aware of when these types of incidents occur."

Editor's note: This article has been updated to include the name of the officer, released by police on Friday.