John Mark Karr faces a variety of charges including first-degree murder in the death of the child beauty queen a decade ago. Karr assured the court in a brief hearing he understood what he was doing and was expected to be sent to Colorado within hours.
Attorney Patience van Zandt said Karr made the decision Monday when she visited him in jail.
"I think Mr. Karr is very anxious to be able to exercise his right to face the charges that are being brought against him, and he knows those charges are in Boulder (Colo.); they are not here," van Zandt told 9News in Denver.
Karr, a 41-year-old teacher, has told reporters he was with JonBenet when she died in the basement of her Boulder home the day after Christmas 1996. He said he loved her and her death was an accident.
He was escorted to Los Angeles Sunday from Thailand, where he had been under investigation for child pornography.
Prosecutors in Boulder have refused to provide details of their evidence suggesting Karr's involvement in the girl's death, and several news organizations, including The Los Angeles Times have appealed for its release.