Chicago has been here before.
In November 1997, Chicago police Superintendent Matt Rodriguez resigned. That same month, a blue-ribbon commission on police reform released its recommendation on how to address police corruption after 10 officers were indicted in the robbery and extortion of drug dealers.
A decade later, in April 2007, Superintendent Philip Cline resigned. A video had emerged of an off-duty police officer brutally beating a female bartender. The incident, along with new information about the torture of suspects by Commander Jon Burge's "Midnight Crew," led to the creation of the Independent Police Review Authority.
On Tuesday, Mayor Rahm Emanuel announced the resignation of police Superintendent Garry McCarthy and the creation of a task force on police reform following the release last week of a video of a police officer shooting 17-year-old Laquan McDonald 16 times.
The city is once again gripped by a familiar story.
Another video of police violence. Another ousted police superintendent. Another committee to study police reform.
"I've seen a good number of superintendents come and go," said Flint Taylor, of the People's Law Center, who has worked on police misconduct cases since 1969. "Unless the culture of the police department is radically changed and the whole structure of the justice system is realigned, changing the head [of the department] by itself is not going to have the impact that we would all hope it would."
Complete overhaul of the criminal justice system appears unlikely, but experts on policing say there are some clear best practices that CPD could learn from other police departments around the country - especially those like Portland, Seattle, and Los Angeles that have signed agreements with the US Department of Justice.
Calls for a Justice Department investigation of the Chicago Police Department have been growing louder - coming from various quarters, from the Chicago Urban League to the Chicago Alliance Against Racist and Political Repression.
On Tuesday, Illinois Attorney General Lisa Madigan wrote a letter to US Attorney General Loretta Lynch requesting a Department of Justice investigation into CPD to determine whether there are "systemic violations of the Constitution or federal law" by the Police Department.
Madigan said: "An investigation into whether there are patterns and practices of civil rights violations by CPD is vital to bringing about the systemic change that is necessary here … Chicago cannot move ahead without an outside, independent investigation into its police department that moves toward improved policing practices and increasing trust between the police and the community."
The Justice Department has investigated 67 police departments since 1994 and become deeply involved in 16 of them.
"It's quite simple," said Samuel Walker, a professor emeritus at the University of Nebraska and a nationally recognized expert on police accountability. "Simply adopt the reforms that are in all the Justice Department settlements in terms of controlling use of force, reviewing patterns and trends, identifying problem officers and keeping policies up to date."
Those four areas that have been the focus of Justice Department interventions have been lagging in Chicago, experts say, despite repeated attempts at reform.
Chicago is fourth among the nation's largest cities in the number of civilians killed by police per capita, according to an analysis by the Better Government Association.
Since September 2007, IPRA has investigated more than 380 police shootings, an average of nearly one a week. Laquan McDonald was one of 127 people killed in shootings by police in Chicago between September 2007 and September 2015, according to IPRA data.
Reviewing patterns of misconduct has been another shortcoming of police accountability in Chicago, experts say.
"The Police Department and IPRA refuse as a matter of practice and policy to look at any pattern evidence, to look at any prior complaints against police officers in any part of their misconduct investigations," said Craig Futterman, law professor and director of the Civil Rights and Police Accountability Project at the University of Chicago.
Ilana Rosenzweig, who led IPRA from its inception in 2007 until 2013, said her investigators conducted searches of an officer's full record of complaints when they started an investigation, but they were limited in what they could get. IPRA has access to complaint history and investigative records but no other internal CPD records, such as discipline histories or performance evaluations. In addition, the union contract limits what actions IPRA can take based on prior complaint history.
"IPRA doesn't have access to the entire personnel file of an officer," said Rosenzweig. "So its ability to perform a holistic review of an officer's past performance is limited."
That kind of review should be done regularly by the Police Department itself, Rosenzweig said.
In theory, it is being done through an "early intervention system," another best practice in police reform, which has been in place in Chicago since 1997 when Mayor Richard M. Daley's blue ribbon commission recommended it.
"The premise is simple," the commission wrote in its final report. "Small problems become big ones if left unattended."
But experts and police watchdogs say the system of flagging officers with numerous civilian complaints or other disciplinary issues is clearly broken in Chicago.
Jason Van Dyke, the officer who was charged with first-degree murder charges for McDonald's death, had previously been the subject of at least 19 misconduct complaints, including at least 10 for excessive force. He was also the subject of two civil lawsuits, one of which cost the city more than $500,000 in damages and legal fees.
"A half-million dollar lawsuit should have risen to the surface as a potential problem," said Dennis Kenney, a former police officer and professor at John Jay College of Criminal Justice in New York City. "If he had so many complaints against him, why did some mid-level supervisor not notice it earlier?"
In 2007, Jeff Kelly Lowenstein wrote about the failures of the early warning system for the Reporter. According to the article, fewer than 1 in 7 officers who had more than 10 complaints between 2001 and 2006 had been placed in the Behavioral Intervention System, based on data analyzed by Futterman's police accountability project.
CPD did not respond to questions this week about how many officers in recent years have been placed in the Behavioral Intervention System, Chicago's early warning program, or whether Jason Van Dyke was one of them.
A police spokeswoman told Lowenstein in 2007 that the department had adopted a new personnel performance system to enhance the early warning system. But Futterman says that few things have changed since then.
"I grow tired of saying this is ineffective, because I think that may be the wrong term," Futterman said. "It's worse than having an ineffective system. The intent of the system is to do exactly what it is doing" - that is, to ignore patterns of abuse by officers like Van Dyke.
In announcing McCarthy's resignation and the creation of the task force on Tuesday, Emanuel noted Chicago's history of police abuse.
"I know the use of excessive force and misuse of authority is not new in Chicago or isolated only in Chicago," he said. "There is a history of it."
Futterman said the history is all too familiar.
"We've been at moments like this one many times in our past - all too many times," he said. "You can replace a superintendent, but without remedying or addressing the underlying issues that have prevented accountability and principles of honesty, we'll be here another year or two from now having the same conversation."
The Chicago Reporter is a non-profit investigative news organization that focuses on race, poverty and income inequality.