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'Black Lives Matter' cases: When controversial killings lead to change

(CNN) Three days, three different resolutions, one common trait: white officers killing black males.

Just this week, we learned two officers will avoid federal charges in the 2016 death of Alton Sterling, a man pinned to the ground before he was shot.

Another officer has been fired for killing Jordan Edwards, a 15-year-old honor student. And yet another officer pleaded guilty after shooting Walter Scott as the 50-year-old was running away.

While officer convictions are rare, such killings have spawned "Black Lives Matter" protests and have led to notable changes -- including reforms to police policy. Here's how some of the most high-profile cases have turned out:

Jordan Edwards, 15

Jordan Edwards

Date of death: April 29, 2017

Where: Balch Springs, Texas

What happened: Officers responded to a house party after reports of underage drinking. Police spotted a car leaving with five people inside -- including Jordan in the front passenger seat.

At first, Police Chief Jonathan Haber said the car was moving "aggressively" toward officers, and officer Roy Oliver fired into the car with a rifle.

But on Monday, Haber corrected himself and said body camera footage showed the car was driving forward -- away from the officers.

The outcomes: Haber fired the officer Tuesday, saying Oliver "violated several departmental policies."

Roy Oliver was fired from the Balch Springs Police Department.

Meanwhile, Jordan's classmates at Mesquite High School are grieving the loss of the beloved football player and straight-A student.

Alton Sterling, 37

Alton Sterling

Date of death: July 5, 2016

Where: Baton Rouge, Louisiana

What happened: Sterling was selling CDs outside a convenience store when police received a call of a man with a gun. Cellphone video showed police tackling Sterling and pinning him to the ground before Sterling was shot. But police said Sterling was reaching for a gun.

The outcomes: On Wednesday, federal prosecutors said they didn't have enough evidence to file charges against Baton Rouge police officers Blane Salamoni and Howie Lake II.

Minutes later, the Louisiana attorney general announced the state will launch an investigation to see whether the officers should face state criminal charges.

But Sterling's death has already yielded change. Baton Rouge Mayor Sharon Weston Broome said $2 million will be spent securing body cameras for the entire police force. On top of that, the city's police training manual will be revised, and officers will receive training in implicit bias, the mayor said.

Walter Scott, 50

Date of death: April 4, 2015

Where: North Charleston, South Carolina

What happened: Officer Michael Slager pulled Scott over for a broken taillight. Scott bolted out of his car, though it's not clear why. His family attorney speculated that Scott's flight stemmed from his unpaid child support "and a fear of maybe going back (to jail)."

As Scott ran away from the officer, a witness captured video of Slager shooting Scott several times in the back.

The outcomes: Slager was fired and indicted for a state murder charge and federal charges, including misleading investigators and excessive use of force.

The state murder trial ended in a mistrial. But on Tuesday, Slager admitted to using excessive force as part of a federal plea deal.

In exchange for his guilty plea for one of the federal counts -- punishable by up to life in prison -- two other federal charges and state charges were dropped.

Scott's death also led to a statewide change: The South Carolina Legislature passed a bill mandating the use of police body cameras.

And the North Charleston City Council agreed to a $6.5 million settlement with Scott's family.

Trayvon Martin, 17

George Zimmerman, left, and Trayvon Martin

Date of death: February 26, 2012

Where: Sanford, Florida

What happened: Martin was walking from a convenience store back to the home of his father's fiancée. Neighborhood watch volunteer George Zimmerman spotted him from his car and called 911, reporting "a real suspicious guy."

"This guy looks like he's up to no good, or he's on drugs or something," Zimmerman told a dispatcher. "It's raining, and he's just walking around."

A scuffle broke out, but there were no direct witnesses. Zimmerman claimed Martin attacked him, hitting him in the nose and knocking him onto the pavement. Zimmerman said he then took out his gun and shot Martin in self defense.

But critics said Zimmerman was unjustified in confronting the unarmed teen, especially since Zimmerman didn't heed a police dispatcher's advice to stop following him.

The outcomes: Zimmerman was charged with second-degree murder but was found not guilty. The acquittal ignited protests across the country, and the "Black Lives Matter" movement gained national prominence.

The case also led to the firing of Sanford Police Chief Bill Lee, who was criticized for not arresting Zimmerman after Martin was killed.

Why this verdict? Five things that led to Zimmerman's acquittal

Eric Garner, 43

An NYPD officer puts Eric Garner in a prohibited chokehold.

Date of death: July 17, 2014

Where: New York City

What happened: Police tried to arrest Garner in front of a store for allegedly selling cigarettes illegally. Garner raised both hands and told officers not to touch him. Seconds later, Officer Daniel Pantaleo grabbed the 350-pound man in a chokehold and pulled him to the sidewalk, rolling him onto his stomach.

The New York Police Department prohibits the use of chokeholds.

Garner, who had asthma, repeatedly said, "I can't breathe! I can't breathe!" while several officers restrained him on the ground. Police said he suffered a heart attack and died en route to a hospital.

The outcomes: A grand jury declined to indict Pantaleo, sparking protests and "die-ins."

Garner's death also spurred a new protest slogan: "I can't breathe," referring to some of his final words before he died. Several professional athletes wore shirts saying "I can't breathe" in silent protest.

Pantaleo offered his condolences to Garner's family and said he never intended to hurt Garner. The police union defended Pantaleo, saying he just wanted to take Garner into custody after the suspect resisted.

New York City eventually settled with Garner's family for $5.9 million. City Comptroller Scott Stringer said the settlement "acknowledges the tragic nature of Mr. Garner's death," but "the city has not admitted liability."

Michael Brown, 18

Officer Darren Wilson, left, and Michael Brown

Date of death: August 9, 2014

Where: Ferguson, Missouri

What happened: Brown was walking with a friend in the middle of a street when Ferguson Police Officer Darren Wilson approached them and told them to walk on the sidewalk.

After that, the narratives split. Authorities said Brown had attacked the officer in his car and tried to take his gun. Others said the teenager was surrendering, his hands in the air to show he was unarmed, when the officer opened fire.

Documents showed that Wilson fired his gun 12 times.

What happened when Michael Brown met Officer Darren Wilson

The outcomes: A grand jury decided not to indict Wilson -- leading to heated and sometimes violent protests in Ferguson and across the country.

A few days later, Officer Wilson resigned from the Ferguson Police Department.

Despite the lack of criminal charges, the Michael Brown case launched a series of reforms. A federal investigation revealed a pattern of abuse by Ferguson's mostly white police force against the city's majority black residents.

The Justice Department found that "many officers" apparently viewed some of the city's black residents "less as constituents to be protected than as potential offenders and sources of revenue."

Black residents were ticketed and cited for minor violations at a higher rate than white residents, the Justice Department said. The investigation also found a spate of racist emails sent by some police and court officials.

Ferguson police report: The most shocking parts

After the scathing Justice Department report, Ferguson police Chief Thomas Jackson resigned. And the Justice Department sued Ferguson to force police reform in the city.

Freddie Gray, 25

Freddie Gray

Date of death: April 19, 2015, seven days after he was injured

Where: Baltimore

What happened: An officer on bike patrol made eye contact with Gray, and Gray fled. Police later found a knife in Gray's pocket and arrested him on a weapons charge.

Officers handcuffed Gray and put him in a police van. At some point, Gray suffered a fatal spinal cord injury. He died seven days later.

Gray's death prompted riots, looting and arson in Baltimore.

The outcomes: Six Baltimore police officers, including three black and three white officers, were charged in connection with Gray's death.

Three officers were acquitted: Edward Nero, a bike officer involved in the initial police encounter with Gray; Caesar Goodson, who drove the van; and Lt. Brian Rice, the highest-ranking officer charged in connection with Gray's death.

Prosecutors dropped charges against the three remaining officers: Garrett Miller; Alicia White and William Porter.

Aside from the criminal trials, Baltimore officials approved a $6.4 million deal to settle all civil claims tied to Gray's death.

The settlement did not "represent any judgment" on whether the officers were guilty or innocent, Mayor Stephanie Rawlings-Blake said.

"This settlement represents an opportunity to bring closure to the Gray family, the community and the city."

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