A convicted sex offender and his wife have pleaded guilty to kidnapping and raping a California girl in a surprise plea deal that will spare their victim and the two daughters she had during her 18 years of captivity from taking the stand at a trial.

A lawyer in the case of a Northern California girl held captive in a backyard compound for 18 years said he expects defendant Phillip Garrido to plead guilty to all charges and his wife to go to trial unless she gets a better plea deal.

Jaycee Dugard, the girl held prisoner in California for 18 years, will be spared from giving pre-trial evidence against her alleged captors.

THE US man charged with kidnapping and raping long- time captive Jaycee Dugard has “a serious mental illness” and “may not be competent to be a defendant,” his defence lawyer said in court papers.

The US man charged with kidnapping and raping long-time captive Jaycee Dugard has "a serious mental illness" and "may not be competent to be a defendant", his defence lawyer said in court papers.