Keeping his eyes down, Gardner, 30, only answered "yes" to the judge's question about whether he understood the charges.
No bail was set, and the prosecutor did not mention any of the details of the alleged crime. Gardner was assigned a public defender for the arraignment, but that lawyer may not represent him at trial.
Prosecutors said the severity of the accusations, including a "special allegation" that a murder was committed during a rape, could carry the death penalty. The decision to seek capital punishment, however, is weeks away.
"The special allegation does make the defendant eligible for the death penalty," Deputy District Attorney Kristen Spieler said at a press conference following the arraignment. "That decision is made by the DA, typically after the preliminary hearing and before a trial."
If the district attorney does not seek the death penalty, the charges carry a penalty of 25 years to life.
Gardner's previous record as a convicted sex offender, prosecutors said, would be presented at trial.
Dr. Matthew Carroll, a court psychiatrist, who evaluated Gardner before his release from prison on the 2000 conviction, had pushed for the maximum sentence, as many as 30 years, and said Gardner "would be a continued danger to underage girls in the community."
Dr. Alex Kalish, a colleague, said Carroll was angry that his recommendations were ignored a decade ago.
"Dr. Carroll told the court that [Gardner] showed no insight and expressed no responsibility and that he is a danger. You can't make a stronger statement than that," said Kalish. "The guy is violent and a predator who shows no remorse.
"There was no effort to consider his report. Apparently the DA did what was expedient to get a conviction. It is frustrating that no one considered the psychiatric input. Why ask for it, if you don't consider it," Kalish said.