CHICAGO (CBS) — Nearly four years after he fired the 16 shots that killed 17-year-old Laquan McDonald, Chicago Police Officer Jason Van Dyke will go on trial starting Wednesday on six counts of first-degree murder, 16 counts of aggravated battery, and one count of official misconduct.

Van Dyke was charged the same day dashboard camera video of the shooting was released, prompting a series of protests in Chicago.

The fallout of the shooting has included the firing of onetime CPD Supt. Garry McCarthy, a Justice Department investigation of the department, and a proposed consent decree outlining major changes for the city’s police force that would be enforced by the courts, if approved.

Van Dyke is the first Chicago police officer in decades to be charged with murder for an on-duty shooting. Here is a timeline of events leading up to the landmark trial:

Oct. 20, 2014: Chicago Police Officer Jason Van Dyke shoots 17-year-old Laquan McDonald 16 times while responding to reports of a person with a knife. McDonald was walking down the street holding a small folding knife while being pursued by police. The police union spokesman, Pat Camden, said at the time: “The officers are responding to somebody with a knife in a crazed condition, who stabs out tires on a vehicle and tires on a squad car. You obviously aren’t going to sit down and have a cup of coffee with them. He is a very serious threat to the officers, and he leaves them no choice at that point but to defend themselves.”

Dec. 8, 2014: University of Chicago law professor Craig Futterman calls for the release of squad car video of the McDonald shooting. Futterman said witnesses at the scene disputed police reports McDonald lunged at officers.

Feb. 24, 2015: Mayor Emanuel forced into April run-off election against Jesus Garcia.

Feb. 27, 2015:  Lawyers for Laquan McDonald’s family approach the city, seeking a settlement in the case before filing a lawsuit.

April 7, 2015:  Mayor Emanuel wins second term, defeating Jesus Garcia 55.5 percent to 44.5 percent.

April 13, 2015: The U.S. Attorney’s Office confirms they are investigating the death of Laquan McDonald. 

April 15, 2015:  The Chicago City Council approves a $5 million settlement with Laquan McDonald’s family.  The agreement requires that the video remain sealed until investigations are complete.

Aug. 5, 2015: Journalist Brandon Smith sues city to force the release of dashboard cam video showing the shooting of Laquan McDonald.

Nov. 19, 2015:  A Cook County Judge orders the city to release the video showing Laquan McDonald being shot by Officer Jason Van Dyke, setting a deadline of Nov. 25.

Nov. 24, 2015:  Chicago Police Officer Jason Van Dyke is charged with first-degree murder for shooting Laquan McDonald.

Nov. 24, 2015:  Chicago police dashboard camera video is released, showing Laquan McDonald being shot 16 times. The video shows that the first shot sent McDonald on the ground as he was walking away from officers.  The video prompts several days of protests in the city.

Nov. 27, 2015:  Activists march on Michigan Avenue, shutting down stores on Black Friday, to protest the death Laquan McDonald, who was a ward of the state and attended Sullivan House High School.

Nov. 30, 2015: Police Supt. Garry McCarthy said his hands were tied in the case. “I couldn’t fire [Jason Van Dyke]. I couldn’t put him in a ‘no pay’ status. I couldn’t discipline him. That’s the law.”

Nov. 30, 2015:  Officer Jason Van Dyke, charged with first-degree murder for shooting Laquan McDonald, is released from jail after posting $150,000 bond.

Dec. 1, 2015:  Mayor Rahm Emanuel forms a “police accountability” task force, a week after the city released a video showing Officer Jason Van Dyke fatally shooting Laquan McDonald.

Dec. 2, 2015:  Mayor Emanuel fires Chicago Police Supt. Garry McCarthy, saying the department needs new leadership.  Protesters celebrate his ouster and demand Mayor Emanuel and State’s Attorney Anita Alvarez resign.

Dec. 3, 2015:  Cook County State’s Attorney Anita Alvarez defends her actions, explaining why it took 13 months to charge Officer Jason Van Dyke and denying there was an attempt to cover up the circumstances surrounding the shooting.

Dec. 4, 2015: Late in the day, the city released hundreds of pages of police reports surrounding the fatal shooting of Laquan McDonald, who was shot 16 times by Officer Jason Van Dyke.  The accounts of officers at the scene differ greatly from what is seen on the dashcam video. Several officers agreed with Van Dyke that the teen was advancing toward Van Dyke in a threatening manner. The video shows McDonald walking away from the officer.

Dec. 6, 2015: The head of the Independent Police Review Authority, the panel tasked with investigating police misconduct, resigns. Scott Ando is to be replaced by Sharon Fairley.

Dec. 7, 2015: The U.S. Justice Department announces a civil rights investigation into Chicago Police Department practices, including use of force and its handling of misconduct complaints against officers.

Dec. 9, 2015: At a special city council meeting, Mayor Rahm Emanuel apologizes for not dealing with the problems in the Chicago Police Department sooner. More protests erupt in the Loop, with a few hundred demonstrators demanding that the mayor resign.

Dec. 17, 2015: Mayor Rahm Emanuel meets with Justice Department officials as the feds launch their civil rights probe of the Chicago Police Department’s “policies and practices” regarding the use of force.

Dec. 30, 2015: Mayor Rahm Emanuel announces plans to change tactics and training regarding the use of force at the Chicago Police Department “to create more time and distance” in tense situations.

March 30, 2016: The Chicago Fraternal Order of Police, the union representing the city’s police officers, hires Officer Jason Van Dyke as a janitor for its headquarters. Van Dyke was suspended without pay after he was charged with first-degree murder for shooting Laquan McDonald.

April 13, 2016: A city task force issues a report finding the Chicago Police Department is plagued by systemic racism, and asserting the police union’s contract is a major obstacle to change.

May 5, 2016: Cook County State’s Attorney Anita Alvarez asks a judge to recuse herself and her office from the Laquan McDonald murder case, and asks for a special prosecutor to take over. Alvarez said she wanted to avoid any possible delays that might result from handing over the Cook County State’s Attorney’s office to her successor after the end of her term in December.

Aug. 4, 2016: Judge Vincent Gaughan later appoints Kane County State’s Attorney Joseph McMahon to take over the prosecution of Officer Jason Van Dyke. McMahon’s team includes assistants Jody Gleason, Dan Weiler, and Joe Cullen; and assistant Winnebago County state’s attorney Marilyn Hite Ross as lead prosecutor.

Aug. 18, 2016: Police Supt. Eddie Johnson moved to fire seven police officers for lying about the circumstances of the Laquan McDonald shooting, in order to justify Officer Jason Van Dyke’s use of deadly force. Two other officers named in a scathing report by the city’s Inspector General already had retired, and Johnson spared a 10th officer from termination.

Oct. 5, 2016: The Chicago City Council votes 39 to 8 to create a new agency tasked with investigating police misconduct. The new Civilian Office of Police Accountability will replace the Independent Police Review Authority.

Jan. 10, 2017: Judge Vincent Gaughan agrees to turn over some of Laquan McDonald’s juvenile records to defense attorneys representing Officer Jason Van Dyke in the murder trial. The judge says he will review the material and rule later which records are relevant at trial. Van Dyke’s attorneys want to use McDonald’s juvenile records to prove he had a violent past and was a threat to officers the night he was killed.

Jan. 13, 2017: A week before the Obama administration leaves office, Attorney General Loretta Lynch releases a Justice Department report taking the Chicago Police Department to task for systemic violations of civil rights, finding officers regularly have used excessive force and discriminated against minorities.

Jan. 19, 2017: Chicago Police Supt. Eddie Johnson suspends four officers who were at the scene of the Laquan McDonald shooting for not ensuring their dashboard cameras were working properly.

Feb. 19, 2017: Two months after leaving office, former Cook County State’s Attorney Anita Alvarez says she feels like she was made to be the scapecoat of the Laquan McDonald shooting. Alvarez defended her record of prosecuting police brutality cases, and said if she hadn’t been in the middle of a campaign for re-election when she charged Officer Van Dyke, “I probably would have been a hero.”

April 4, 2017: Attorney General Jeff Sessions issues a memo calling into question whether the Justice Department will monitor reforms at the Chicago Police Department. Sessions says local law enforcement should be responsible for determining the best practices for policing, not the federal government. Mayor Rahm Emanuel and Chicago police brass say reforms should move forward with or without a federal consent decree.

May 17, 2017: The Chicago Police Department finalizes new rules regarding the use of force, aiming to focus on conflict de-escalation to prevent loss of life.

June 27, 2017: Three Chicago police officers are indicted for obstruction of justice and conspiracy, for allegedly trying to cover up the circumstances of the Laquan McDonald shooting. Det. David March, and patrol officers Joseph Walsh (Van Dyke’s former partner) and Thomas Gaffney allegedly lied about the shooting to “prevent or shape” an independent probe of McDonald’s death. March, Walsh, and Gaffney have pleaded not guilty, and are scheduled to go on trial in November. The department has moved to fire Walsh. Gaffney remains suspended without pay. March has retired from the force.

Aug. 29, 2017: Illinois Attorney General Lisa Madigan and Mayor Rahm Emanuel announce an agreement clearing the way for federal court oversight of police reforms. Madigan files a federal lawsuit to force court supervision of changes in police training, discipline, oversight, and use of force.

March 23, 2018: Former CPD Supt. Garry McCarthy announces plans to run against Mayor Rahm Emanuel in the 2019 mayoral race. McCarthy defended his record on the Laquan McDonald case, saying he did the only thing he could about the shooting, placing Officer Jason Van Dyke on administrative leave.

April 28, 2018: Judge Vincent Gaughan orders the release of dozens of documents filed in the murder case against Officer Jason Van Dyke. Previously, most court filings had been kept under seal, before attorneys for several Chicago media outlets asked the Illinois Supreme Court to force Gaughan to make them public.

July 17, 2018: Judge Vincent Gaughan schedules Officer Jason Van Dyke’s murder trial to begin on Sept. 5, 2018, nearly four years after the officer shot and killed Laquan McDonald.

July 27, 2018: Illinois Attorney General Lisa Madigan and Mayor Rahm Emanuel announce a proposed consent decree regarding police reforms. The public has 21 days to respond before court hearings to decide if a judge will approve the plan.

Aug. 3, 2018: Defense attorney Daniel Herbert formally asks Judge Vincent Gaughan for a change of venue, arguing Officer Jason Van Dyke cannot get a fair trial from a Cook County jury, A defense expert testifies he conducted a study finding 87 percent of people in Cook County have an opinion in the case, and 74 percent of those polled believe Van Dyke is guilty. Judge Vincent Gaughan delays ruling on the request for a change of venue until after jury selection begins, to determine if a fair jury can be selected from Cook County residents.

Aug. 16, 2018: Laquan McDonald’s mother, Tina Hunter, appears in court to testify about her son in a closed hearing. Hunter, who has never spoken publicly about the shooting, had not showed up for previous hearings, despite attorneys for Officer Jason Van Dyke seeking to question her about McDonald’s allegedly violent history. It’s unclear yet if Hunter will have to testify at trial.

Aug. 28, 2018: Jason Van Dyke gives his first interview since the shooting, telling the Chicago Tribune “I’m not racist.” The officer does not discuss details of the shooting itself, but says he prays for Laquan McDonald’s family every day, and says he’s “extremely nervous” about the upcoming trial.

Aug. 30, 2018: The special prosecutor’s office handling the case against Jason Van Dyke files a motion asking for his bail to be increased or revoked, and for the officer to be held in contempt of court, arguing the Tribune interview violated a gag order issued by the judge in the case.

Sept. 1, 2018: Judge Vincent Gaughan delays ruling on the request to revoke or increase Van Dyke’s bail until Sept. 6, and says a hearing on the contempt charge will not be held until after the murder trial.