The police officers were indicted for allegedly engaging in a conspiracy in an attempt to prevent or shape the independent criminal investigation into McDonald's police-involved shooting death, according to a release from Special Prosecutor Patricia Brown Holmes.
Det. David March, 58, and patrol Officers Joseph Walsh 48, and Thomas Gaffney, 43 were each charged with conspiracy, official misconduct and obstruction of justice, according to court documents filed in Cook County, Illinois on Tuesday.
“The indictment makes clear that these defendants did more than merely obey an unofficial ‘code of silence.’ Rather, it alleges that they lied about what occurred to prevent independent criminal investigators from learning the truth,” Holmes said.
March, Walsh, Gaffney and others allegedly conspired in the "critical early hours and days" following the shooter "to conceal the true facts of the events surrounding" McDonald's death "to shield their fellow officer… from criminal investigation and prosecution," the indictment states.
Prosecutors also accuse the officers of coordinating their activities to protect each other and other members of the department by furnishing false information, making false police reports, failing to report or correct false information, ignoring contrary information or evidence, obstructing justice, failing to perform a mandatory duty and performing acts each knew he was forbidden to perfect.
The indictment also alleges that the officers failed to locate, identify and interview at least three witnesses whose information was inconsistent to accounts given by members of the police department.
March is a police veteran of more than 30 years, and Walsh and Gaffney have both been with the police department for about 20 years, according to the release.
All three officers are expected to be arraigned on July 10.
ABC News could not immediately reach March, Walsh and Gaffney for comment. It is unclear if they have retained attorneys.
Their status with the department was not clear.
In a statement, Chicago Police Superintendent Eddie Johnson said McDonald's death "forever changed the Chicago Police Department."
"...I am committed to implementing policies and training to prevent an incident like this from happening again," Johnson said. "Throughout this investigation, CPD has fully cooperated with prosecutors and will continue to do so. We will also continue to implement meaningful reforms that build community trust, provide greater training and resources to our dedicated officers, and make Chicago safer."
McDonald was shot 16 times in October 2014 by Chicago Police Officer Jason Van Dyke. Holmes was appointed by Cook County Judge LeRoy K. Martin, Jr. in 2016 to investigate whether charges should be filed in McDonald's death.
Police dash cam footage showed that McDonald was armed with a knife but not moving toward the responding officers when he was shot. The release of the footage in November 2015 caused nation-wide protests.
Van Dyke's attorney, Dan Herbert, alleged in a statement that the "new indictment is further proof that the government is determined to prevent Jason Van Dyke from receiving a fair trial by silencing potential witnesses."
"Apparently, the rule of law is trumped by special interest groups and politicians," Herbert said. "If the conspiracy alleged in the indictment is true, which is false, then this is the tip of the iceberg."
In response to the charge that the officers were conspiring ensure that "the public would not see the video recordings of the event," Herbert said that "preventing the release of a video is far beyond the pay grade of any police officer."
"If true, then the entire command staff of the police department, including the former and current superintendents, must be part of the conspiracy considering they were aware of the reports and video when they signed off on the shooting," Herbert said.
A grand jury investigation into the case is continuing, Holmes said. The Fraternal Order of Police did not immediately return ABC News' request for comment.