As noted by the other author, Arizona does not have the authority to issue a subpoena for a foreign (out of state) entity. The process is complex and will involve an attorney both in Arizona and in Texas. First you need to get a formal order from the Court authorizing the Subpoena on the Texas DFPS, this will require a Motion. Once issued, the Subpoena will have to be "domesticated" in the foreign jurisdiction by filing and opening up a new case matter in Texas. The Texas Court will then approve of the Arizona Subpoena and allow it to be issued by the Texas court and served in Texas.
Your better, quicker, cheaper, route is to make a Public Records Request for the documents you seek. Since you are involved in the circumstances for which the reports were issued, you might be able to obtain those records even though they are typically protected from disclosure.
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Arizona does not have authority to subpoena records from outside the stats so there are no forms for interstate subpoenas. You probably want to consult with a Texas attorney or contact Tx DFPS to determine is you are entitled to these documents and the steps necessary to obtain them.
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