My question involves court procedures for the state of: ID

I have obtained a subpoena to retrieve the text message conversation from an individuals phone. I need to export the entire conversation with a certain individual stored on their phone and save it as a PDF and print it out or email it. There are a number of free apps which will do this. My question is if I have the Sheriff's department serve the subpoena can they collect the text message conversation at the same time or can the person being served refuse to comply? If we don't collect the text messages right away the individual has an opportunity to delete some of the text messages which I believe they will do.