A law firm can provide criminal defense services for the defendant in the same case at the same time, and can also file an incidental civil action on behalf of the defendant.
According to the provisions of the Criminal Procedure Law of People's Republic of China (PRC), the defendant in an incidental civil action may entrust his defense lawyer as an agent ad litem or entrust him separately. In other words, the parties to a criminal incidental civil action may entrust a lawyer as an agent ad litem.