The Sheriff's office is a political entity in Arizona. Political entities have special rules about how they are sued. For instance, the sheriff's office needs to be served with a Notice of Claim within 180 days of the date when the claim accrues. If the Notice of Claim is not served within that time frame, the case will likely be dismissed by the court. Also, the Complaint must be filed in the court within one year of the date that the claim accrues. If it is not filed within this time frame, the Complaint will likely be dismissed.
In a case against the Sheriff's office, you would name the Sheriff as a defendant, along with any other persons who caused damages in your case. You should name the actual Sheriff by name, not the "Sheriff's Office," as the Sheriff's Office is not a juridical entity, and cannot sue or be sued.
Each case is specific, and in cases against state agencies (like the Sheriff), you should probably contact an attorney who can help you properly frame your Complaint so your rights are protected.
This post is intended for educational purposes only, and is not meant to be construed as legal advice.