The police can pull up the text messages from ten years ago.

Generally within 6 months. The public security bureau can find short messages, but it can't just check them. People's Republic of China (PRC) citizens' freedom and privacy of communication are protected by law. When public security organs and procuratorial organs check communication according to the procedures prescribed by law, no organization or individual may infringe upon citizens' freedom and privacy of communication for any reason, except for the needs of national security or criminal investigation. The inquiry of SMS should be carried out at the operator's office, and the public security needs formal procedures to authorize the operator to inquire about other people's communication records. Of course, it can only be targeted and cannot be authorized casually. The public security organ has this power, but it must be after the criminal case is filed. However, this kind of evidence can only be obtained when the case investigation is needed, and it can only be used in criminal proceedings, and irrelevant personnel cannot consult and copy it.

Criminal Procedure Law of the People's Republic of China

Article 148

After filing a case, the public security organ can take technical investigation measures against crimes endangering national security, terrorist activities, organized crimes of underworld nature, major drug crimes or other crimes seriously endangering society after strict approval procedures according to the needs of investigating crimes. Technical reconnaissance measures include electronic monitoring, telephone monitoring, electronic monitoring, secret photography, video recording, mail inspection and other secret special technical means, and naturally short message inquiry can also be carried out.