A judge on Thursday dashed the hopes of four former Minneapolis police officers charged in the killing of George Floyd.

Hennepin County District Judge Peter Cahill dropped a lower-level murder charge against the former Minneapolis police officer who pressed his knee into George Floyd's neck for more than nine minutes, but kept a higher-level murder count against him. Cahill also ruled that there was enough evidence for jurors to decide whether three other former officers should be convicted of aiding and abetting charges.

The judge dismissed a third-degree murder count against Derek Chauvin but ruled that he will remain charged with one count each of second-degree unintentional murder and second-degree manslaughter.

The development prompted Gov. Tim Walz to issue an executive order activating the Minnesota National Guard to provide "public safety services and security assistance" if needed.

Minneapolis Mayor Jacob Frey requested support from the Guard "out of an abundance of caution and for the sake of preparedness," spokesman Mychal Vlatkovich said.

Civil unrest following Floyd's May 25 death led to arson and vandalism costing many millions of dollars.

Cahill dismissed the third-degree murder charge because the law applies when someone causes the death of another person while committing an act inherently dangerous to others. No one else was put at risk in the Floyd case, so the charge must be dismissed, he ruled, citing Minnesota Supreme Court precedents.

A Minnesota Supreme Court decision in a 2014 New Brighton murder case stated that third-degree murder " 'cannot occur where the defendant's actions were focused on a specific person,' " Cahill wrote.

The third-degree murder count was seen by many in the legal community as "defective" when Hennepin County Attorney Mike Freeman charged it on May 29.

It cost Freeman control of the case.

Some believed that second-degree murder should have been charged instead, and took their concerns to Walz.

"It was an inappropriate charge from the get-go, and it raised a lot of concerns for us as a community law firm," said Sarah Davis, executive director of the Legal Rights Center (LRC). "It really points to what the community has been saying all along about this prosecution, which is that it truly needs to be truly independent from the Hennepin County Attorney's Office."

Michael Friedman, who was the executive director of LRC at the time, said the LRC raised the issue with the American Civil Liberties Union (ACLU) of Minnesota.

The ACLU dispatched an "emergency communication" to the governor. The next day Walz appointed Attorney General Keith Ellison as lead prosecutor in the case.

A few days later on June 3, Ellison's office charged Chauvin with second-degree murder.

"The ACLU-MN argued that more severe charges were necessary to seek justice for George Floyd, and that the way the law is written the third-degree charge wasn't likely to stand," ACLU-MN Executive Director John Gordon said in a written statement. "Today was a good day for achieving justice for George Floyd."

Gordon said in an interview that Cahill's decision was not a setback, but rather a step toward "clearing away some of the underbrush" so the accurate, more serious charge could be pursued at trial.

Freeman issued a written statement noting that his office was involved in charging the higher count.

"Our office did file second-degree murder charges against Chauvin," said a statement from his office. It notes that the complaint carries the signatures of both Ellison and Freeman.

Third-degree murder is an uncommon count that some defense attorneys have said didn't suit the Floyd case. The charge best fits a situation such as someone shooting randomly into a moving train and killing someone, some have said.

The legal definition of the charge states that it applies when someone causes a death while perpetrating an act "eminently dangerous to others" and while "evincing a depraved mind," a standard that can be difficult for attorneys and judges to explain to jurors.

Freeman's office initially filed the charge and a manslaughter count against Chauvin four days after Floyd was killed.

Don Lewis, who served as a special prosecutor in the Ramsey County case against Jeronimo Yanez, the former St. Anthony police officer who was acquitted in the death of Philando Castile in 2016, has said that the third-degree murder count was viewed by many as "defective" in the Floyd case.

"I'm still somewhat perplexed by the way it was charged," Lewis said several months ago.

Similar questions about third-degree murder also arose when Freeman's office tried former Minneapolis police officer Mohamed Noor in 2019 for fatally shooting Justine Ruszczyk Damond. But prosecutors noted at trial that Noor fired his gun across his partner's body and out a squad car window toward occupied homes while a teenager was bicycling nearby.

Jurors convicted Noor of the count along with second-degree manslaughter. They acquitted him of second-degree murder.

Lewis hypothesized that Freeman charged Chauvin with third-degree murder because he was "comfortable" with it given the outcome at Noor's trial.

Cahill's rulings resolved issues that had some activists worried that Floyd's death would go unheard in the court system like many previous cases of police killing Black civilians. And the rulings quelled fears that Minneapolis would once again erupt in protest, arson and looting if the former officers were to avoid criminal prosecution.

Cahill also ruled that Chauvin's former colleagues — J. Alexander Kueng, Thomas Lane and Tou Thao — will remain charged with aiding and abetting murder and manslaughter.

Attorneys for each of the defendants had filed motions to dismiss the charges against their clients.

Civil rights attorney Ben Crump, who is representing Floyd's family, said he's confident Ellison's office will prevail at trial.

"We are gratified that the court preserved eight of the nine charges against Derek Chauvin, including the more serious second-degree murder charge for which we expect a conviction," Crump said in a written statement.

Ellison issued a statement noting that the rulings were a positive development.

"This is an important, positive step forward in the path toward justice for George Floyd, his family, our community, and Minnesota," the statement said.

Cahill gave Ellison five days to appeal the dismissal of the third-degree count.

The trial is scheduled to begin March 8. Cahill is weighing motions to move it out of the county based on pretrial publicity, civil unrest and recent threats made against Chauvin and his attorney.

The judge said at a Sept. 11 hearing that he did not have enough information to decide the matter yet, signaling a possibly longer wait on that matter.

Cahill is also expected to rule soon on a motion filed by Ellison's office to try the four defendants in one trial instead of separately.

Staff writer Liz Navratil contributed to this report.