Three Chicago police officers were found not guilty Thursday of attempting to cover up the 2014 shooting of 17-year-old Laquan McDonald.

Det. David March and officers Joseph Walsh and Thomas Gaffney were acquitted Thursday of felony charges of conspiracy, official misconduct and obstruction of justice for allegedly attempting to prevent or shape the investigation.

Judge Domenica Stephenson said prosecutors failed to prove conspiracy or obstruction of justice and that the dashcam video of McDonald's death did not necessarily tell the whole story. She noted inconsistencies in witness testimony, a lack of proof that the three officers conspired to cover up the shooting and said other evidence in the case was "nothing more than speculation."

After hearing the words "not guilty," families of all three officers openly cheered and clapped. Fellow officers in the packed courtroom were seen congratulating the three and shaking their hands.

"Unbelievable," Walsh said as he walked out of the courtroom, shaking his head.

Critics of the department in the wake of the shooting called the decision a "setback." Some vowed to protest, while others called on supporters to vote in the city election next month.

"Today we’re disappointed. We’re devastated. I mean, we’ve been fighting for justice for Laquan for four years," said activist William Calloway, who had fought to get the video of McDonald's shooting released.

"We want to heal. We want to get past this saga of Laquan," he said.

Calloway urged supporters not to protest, but to vote.

Judge Stephenson announced the long-awaited verdict more than a month after the final witness testified in the trial.

Prosecutors claimed the three conspired in lying and falsifying reports to conceal what happened the night Officer Jason Van Dyke fatally shot McDonald.

Van Dyke was convicted of second-degree murder and 16 counts of aggravated battery in October 2018. He is slated to be sentenced Friday.

All three officers were on the scene on Oct. 20, 2014, when Van Dyke fired 16 shots at McDonald, according to prosecutors.

Walsh, 48, was Van Dyke's partner at the time and allegedly gave conflicting accounts about the events leading up to the shooting, which was captured on dashcam video.

March, 58, was lead detective at the time of McDonald's shooting death. He wrote in reports after McDonald's death that Van Dyke was in defense of his life when he backpedaled and opened fire — a narrative that appeared to contradict the dashcam video released more than a year later.

In a June 2017 statement announcing the charges, special prosecutor Patricia Brown Holmes alleged that March, Walsh and Gaffney, 43, "conspired in the critical early hours and days… to conceal the true facts of the events surrounding the killing of Laquan McDonald… to shield their fellow officer from criminal investigation and prosecution."

The officers were accused of lying about what occurred and mischaracterizing the video recordings so that investigators would not know what happened and that the public would not see the video recordings, Holmes claimed.

Defense attorneys contended that there was no evidence of a cover-up. They argued the three officers stood to lose their freedom over a few disputed words.

"She concluded, as we did a year before, that there never was a case here," said defense attorney Todd Pugh.

"They never should have been here. Ever," said James McKay, March's attorney.

"This case wasn’t even close, and three innocent men had to be put through hell," he said.

Holmes said after court Thursday that while prosecutors "disagreed with the ruling," they respected it.

"We hope this has been a crack in the wall of the code of silence and that others will think twice about engaging in conduct that will land them in a situation such as this," she said.

City officials noted that since the 2014 shooting and later release of dashcam fotoage, reforms in the city's police department have been implemented.

“While the court process in this case is over, our work to ensure the systemic reform underway at the Chicago Police Department continues," Chicago Mayor Rahm Emanuel and Supt. Eddie Johnson said in a statement. "CPD is on the road to reform with no off-ramps. Unlike past reforms, these will stand the test of time."