DETROIT, Michigan (CNN) -- Not guilty pleas were entered Tuesday for Detroit Mayor Kwame Kilpatrick and his former chief of staff in a scandal in which they are accused of lying under oath about an affair.
Detroit, Michigan, Mayor Kwame Kilpatrick appears in court Tuesday for his arraignment.
Kilpatrick and his former chief of staff, Christine Beatty, face felony charges of perjury, obstruction of justice and misconduct in office.
Kilpatrick has been at the center of a scandal since January when the Detroit Free Press reported he exchanged romantic text messages with Beatty, contradicting testimony the pair had given in a whistle-blower trial.
Both Kilpatrick and Beatty declined to enter pleas Tuesday before 36th District Court Chief Magistrate Steven Lockhart. Lockhart entered the pleas on their behalf.
Lockhart set a $75,000 personal bond for both defendants. If convicted on all charges, Kilpatrick could face 80 years in prison and/or $40,000 in fines. Beatty could face 75 years and/or $30,000 in fines.
Both are free to leave Michigan but are due back in court June 9.
"This is a historic moment, a sad moment. No sitting mayor of Detroit has ever been charged with a crime," Detroit Free Press reporter Jim Schaefer told CNN on Tuesday
The case is about much more than sexually explicit text messages, Wayne County Prosecutor Kym Worthy said earlier Tuesday.
"Text messages are just part of the case," Worthy said on CNN's "American Morning." "We have much more evidence than that.
"It is not just about the sexual affair. It is about lying under oath. It is about betraying the public trust. It is about using $8.4 million of the taxpayers' money to cover up that information from coming out." Watch Worthy explain why she brought charges »
The Detroit City Council and Free Press have called for Kilpatrick's resignation. But at a press conference Monday, the mayor defiantly said that he would stay on the job and fight the charges.
"This has been a very flawed process from the beginning," he said. "I look forward to complete exoneration." Watch Kilpatrick defend himself »
Kilpatrick's attorney, Dan Webb, has said the thousands of text messages that might be used as evidence against the mayor were obtained illegally.
Worthy denied that allegation.
"I can't speak to how anybody else obtained those messages," she said Tuesday. "But I know that we obtained them lawfully."
Webb also contended Monday that Kilpatrick may be the only person ever charged by the Wayne County prosecutor's office with perjury based on statements made in a civil case.
"It is always reserved for criminal cases," Webb said. "But out of all the allegations over the years, they have only decided to bring charges against one person. That brings up an issue called selective prosecution, an issue I intend to bring up with the trial judge."
Last week, the City Council voted 7-1 to ask Kilpatrick to resign, a city clerk said. The vote was nonbinding, and Kilpatrick has continued on the job amid the fallout from the scandal.
In January, the Free Press reported that in an analysis of nearly 14,000 text messages on Beatty's city-issued pager it found some from 2002 and 2003 that indicated she and the mayor were having an affair.
Allegations of an affair arose last summer during the whistle-blower trial in which two officers sued Kilpatrick and the city. The officers alleged Kilpatrick had retaliated against them for their roles in an internal investigation involving possible misconduct in Kilpatrick's security unit, according to court documents.
In testimony in August, Kilpatrick and Beatty both denied having a romantic relationship.
The lawsuit, brought by Deputy Chief Gary Brown and Officer Harold Nelthrope, ended with the jury awarding judgment against the city for $7.9 million, including interest, according to the officers' attorney, Michael L. Stefani. The city then agreed to a settlement involving Brown, Nelthrope and another related case for about $8 million.
Kilpatrick and Beatty were not personally liable for the settlement amount because the suit was related to their roles as city officials. E-mail to a friend
CNN's Chris Lawrence contributed to this report.