The U.S. Attorney’s Office announced to media outlets over the weekend that they would be leading an investigation into the shooting and death Michael Brown. The investigation into the Ferguson police’s fatal encounter with an unarmed black teenager will be carried out by FBI agents who have already begun collecting statements and evidence in Missouri. Last Friday, the Chief of Police identified Officer Darren Wilson as Brown’s shooter. As the investigation and possible criminal indictment unfolds, many in Ferguson and across the nation are concerned that Brown and his family won’t get justice.

Looking at the outcomes of past investigations of well-known police brutality cases could shed some light on how this investigation will play out.

Officer Johannes Mehserle

In 2009, San Francisco transit police officer Mehserle shot and fatally wounded 22-year-old Oscar Grant at a metro station. Transit police detained Grant and other unarmed young black males for suspected involvement in a fistfight. Although Grant was lying facedown on the floor, held and surrounded by officers, Mehserle shot Grant for resisting arrest. The events were captured on video and went viral, sparking a massive protest. The story was depicted in the critically acclaimed drama Fruitvale Station.

Despite the prosecution’s call for second-degree murder, a jury only convicted Mehserle of involuntary manslaughter and he was sentenced to the minimum of two years with double credit for time served. Mehserle’s defense hinged on the fact that he believed he was using a Taser instead of a gun. The police union raised money and paid for Mehserle’s $3 million bail as well as his defense fees.

Notwithstanding Mehserle’s attempts, he is not allowed to return to the force. After being released from prison, Mehserle went to court for a separate police brutality charge that occurred in 2008.

In 2010, the U.S. Justice Department opened a civil rights investigation into Mehserle, but no charges have been filed yet. A similar civil rights investigation has been opened in Ferguson.

Officer Joseph Wolfe, Officer Manuel Ramos, Corporal Jay Cicinelli

In 2011, Officers Wolfe, Ramos and Corporal Cicinelli brutally beat Fullerton, CA homeless man, Kelly Thomas, who was unarmed during the encounter and had a history of mental illness, which at least one officer was aware of at the time. During the officers’ arrest of Thomas for suspected car vandalism, Thomas “resisted arrest” by slowly backing up after being verbally threatened by one of the officers. The officers, who had Thomas surrounded, relentlessly beat him with their flashlights and Tased him until he was put into a coma. Thomas died of injuries relating to the beating. The incident went viral when a 35-minute video of the beating while Thomas helplessly cried out for his father was released.

Prosecution called for the officers’ conviction of second-degree murder and involuntary manslaughter. Officer Ramos and Cpl. Cicinelli were acquitted at the same trial while a pending case on Officer Wolfe was dropped after the others’ verdict. The officers’ defense attorney proclaimed, “These peace officers were doing their jobs… They did what they were trained to do.” The officers’ defense and bail were paid through a union-sponsored legal insurance fund in addition to donations received from sympathetic officer associations.

The officers were put on paid administrative leave for several months after the fatal encounter. Eventually, the three officers were fired by the police department a year after the incident. At least one of the officers qualified for and still receives a California state pension.

An FBI investigation focused on constitutional rights violations of Thomas still continues three years later and has not yielded any charges.

Officer Sean Carroll, Officer Edward McMellon, Officer Kenneth Boss, Officer Richard Murphy

Four New York City plain-clothed officers shot unarmed 23-year-old Guinean immigrant, Amadou Diallo, 41 times outside of his apartment building in 1999. The officers stopped Diallo on the suspicion that he matched the description of a wanted rapist. Once officers approached Diallo and asked him to show his hands, a confused Diallo ran up the steps towards his apartment and attempted to pull out his wallet and identification from his jacket pocket. Mistakenly believing that Diallo pulled a gun, the four officers opened fire.

The NYPD’s internal investigation found that the officer had acted within policy. Although the Bronx District Attorney’s Office called for second-degree murder and reckless endangerment, a jury acquitted the officers on all charges. Again, the defenses main argument was that the officers were just carrying out the regular duties of an officer and reacted according to department policy.

All officers were allowed to remain on the force. Officer Boss is still on the force and had his gun license reinstated a few years ago.

Though the verdict ignited a wave of protest and media controversy, the case never went any further.

History Repeated?

The circumstances these three famous incidents of police brutality are eerily similar to each other and to the Michael Brown shooting. While history isn’t an exact predictor of the future, these cases certainly illuminate common patterns. Other cops and police associations tend to rally around and support questionable officers despite the results of investigations, federal civil rights investigations tend to be started but not yield any charges, and resisting arrest or police orders often justifies death.

Even if Brown’s shooter, Darren Wilson is indicted on criminal charges, it won’t be a surprise if he isn’t convicted. Former federal prosecutor and law professor Lawrence Rosenthal states, “Police officers are very unusual kinds of defendants because … they are seen as acting not in their own interests but acting to protect the public at large, the very people sitting on their jury,” Rosenthal said. He says that jurors are most likely to acquit under these circumstances.

If you expect justice to result from the investigation and possible trial of Darren Wilson, history says to hold your breath.