HOUSTON -- A Harris County grand jury indicted four former City Hall employees accused of accepting unauthorized bonuses on criminal charges, KPRC Local 2 reported Friday.

Rosie Hernandez, Christopher Mays, Theresa Orta and Florence Watkins are accused of accepting more than $143,000 in unauthorized bonuses.

A total of nine indictments were handed down. Each received indictments on felony theft by a public servant and tampering with a government document. Watkins received a second indictment on suspicion of tampering with a government document.

Mayor Pro-Tem Carol Alvarado, who testified before the grand jury on Wednesday, was not indicted.

"I want to thank the Harris County District Attorney and the members of the Grand Jury for their diligent and thorough review of the facts," Alvarado said in a written statement. "In many ways this is a sad day, because it is a stark reminder that four employees of the office of the Mayor Pro Tem betrayed my trust and, more importantly, the trust of the people of the city of Houston. They are now, appropriately, in the hands of the criminal justice system."

"She accepts responsibility for not providing adequate oversight of her office. She's taken steps to make sure it never happens again," said Joe Householder, Alvarado's spokesman.

The four former employees worked in Alvarado's mayor pro-tem office. They were fired in March.

Mays' attorney said he wasn't surprised at the indictments.

"Neither one of us was surprised, but we were both disappointed and that exactly was what his response was -- he was sad to hear it," attorney Dick Wheelan said.

White released the following statement after the grand jury's finding.

"As I said after I initiated the investigation, nobody should be permitted to set and authorize their own bonuses without clear approval by their supervisor. We appreciate the diligence and thoroughness of the district attorney and his office," White said.

Prosecutors said the investigation into the City Hall bonus scandal may not be over. They plan to look at other city departments but would not elaborate.