Legal Question in Criminal Law in California

Since you have provided absolutely no facts in your question and I have no knowledge of the circumstances surrounding your question it is impossible to give you any kind of accurate answer. However, sure a county jail can house a State Prison inmate. When inmates in prison are testifying in other cases or appearing on some other issues in their case, the department of corrections will transport them to local jails. They will stay at the jails until they are no longer needed. Then they are transported back. However, the reason an inmate was transported to a county jail may have nothing to do with testifying. It really depends on the circumstances and there could be a lot of different reasons why an inmate has been left in the custody of the jail. However, without facts, no one can give you any kind of accurate answer to your question. Good Luck