Minnesota Attorney General Keith Ellison said Friday that he has "every expectation" authorities will press charges against the Minneapolis police officers involved in the death this week of George Floyd.

In a live interview on CNN, Ellison attributed the lack of charges several days since Floyd died to prosecutors with the Hennepin County Attorney's Office "trying to be careful" to make sure they have a case that is "air tight" and won't fall apart because of pressure to file more quickly than the evidence allows.

"I have every expectation that they will be [filed]" soon, said Ellison, while pointing out that his office is not the one to make charges happen.

At the same time, he said, patience among the public is needed because, "If it's not a solid case, we will be sorry later."

Authorities have yet to arrest Derek Chauvin, the officer who held his knee to Floyd's neck on the pavement for many minutes Monday as a witness' cellphone camera rolled until he fell motionless. Floyd was taken to a hospital from the south Minneapolis intersection and declared dead that same night.

Chauvin and the three other officers with him have been fired and remain free as state prosecutors weigh criminal charges and the U.S. Attorney's Office investigates whether Floyd's constitutional rights were violated.

A day earlier, County Attorney Mike Freeman said that his office is "going to investigate it as expeditiously, as thoroughly and completely as justice demands. Sometimes that takes a little time. And we ask people to be patient."

U.S. Attorney Erica McDonald also said Thursday that time is needed because "it is imperative that the [federal] investigation is done right and done right the first time, and that is what we are going to do."

Pressing Ellison further Friday on live television, CNN anchor Alisyn Camerota asked Ellison what yet to be released details from an autopsy could lead to anything other than the officers being charged in Floyd's death.

"I can't believe what can be in there to change my mind," Ellison said, pointing out that was his personal observation and not representative of his office or any other government agency.

The Hennepin County Medical Examiner's Office disclosed Tuesday that Floyd was declared dead at 9:25 p.m. Monday, but cause and manner behind his death remain undetermined "pending further testing and investigation."

Late Thursday, while calls grew louder from Twin Cities activists, national figures and others for swift action by law enforcement against the four officers, the examiner's office said its work on the autopsy into Floyd's death cannot be rushed.

The medical examiner cautioned in a statement that "the autopsy alone cannot answer all questions germane to the cause and manner of death, and must be interpreted in the context of the pertinent investigative information and informed by the results of laboratory studies."

Star Tribune staff writer Andy Mannix contributed to this report.