Each of them pleaded not guilty to charges of abusing inmates and filing false reports at the Placer County Jail.
Madden, Villanueva and Yaws were arrested in May after detectives say a jail supervisor stumbled upon surveillance video of the three abusing inmates.
One of the inmates who investigators say was assaulted told FOX40 he was punched in the face repeatedly.
The trio, free on bail since their arrests, refused to comment outside court.
Yaws' attorney did speak to the press.
"She entered not guilty pleas and she's presumed innocent at this time, and we are going to get the discovery, all the information, and go from there," attorney John Gonzalez said.
FOX40 spoke with a spokesperson from the Placer County Sheriff's Department who says they are still working to put together their professional standards unit that will handle situations like the one involving the three officers.
The three co-defendants are scheduled to be back in court on Aug. 28.