By Matthew Holloway |
The Pinal County Attorney’s Office has closed its review of allegations involving former Pinal County Sheriff Mark Lamb after determining that the evidence reviewed did not establish a violation of Arizona criminal law.
Pinal County Attorney Brad Miller announced Monday that his office completed its review of allegations and materials submitted regarding Lamb and concluded that “no abuse of power or other crime occurred.” The matter is now closed.
The review followed allegations involving Lamb that were submitted to the Pinal County Board of Supervisors in 2020. According to the preliminary inquiry released by Miller’s office, Tim Gustafson delivered a packet of information to the Board of Supervisors on Jan. 29, 2020, regarding allegations against Lamb, who was then serving as Pinal County sheriff.
“Public officials are entitled to the same due process and the same scrutiny as every other citizen. Not more. Not less,” Miller said. “When allegations are presented to this office, our responsibility is to determine whether a crime occurred, not whether a narrative is politically convenient. This office does not prosecute rumors, politics, social media campaigns, or headlines. We prosecute crimes. We follow the facts, we follow the law, and we follow the evidence. In this case, the evidence does not establish that any law was broken.”
The inquiry states that in May 2026, former Pinal County Attorney Kent Volkmer told the media that he had conducted a cursory investigation into the Lamb matter from 2020. Miller said he directed staff to locate the investigation so he could review it, but no investigation was found.
“No investigation was found, and not a single investigator at the Pinal County Attorney’s Office, including the former Chief of Investigations, could recall that such an investigation had ever been conducted,” the preliminary inquiry states.
Chief Hank Mueller then requested the materials provided by Gustafson, or any other individual, to the Pinal County Board of Supervisors. Those materials were provided on May 29, according to the inquiry.
On June 3, an alleged victim came forward and provided more than 3 gigabytes of additional materials for review, including audio, video, documents, and social media materials. Miller said he reviewed all of the materials in preparation for the preliminary inquiry.
The Pinal County Attorney’s Office said it reviewed records, witness statements, text messages, social media posts, recorded calls, and other communications before concluding that the evidence did not establish criminal conduct.
The inquiry listed three conclusions: that there was no evidence Lamb acted in a criminal manner; that there was no evidence Volkmer performed any investigation into the matter despite what he told the Arizona Republic in May; and that there was no evidence Lamb was a victim of a crime or asked Volkmer to investigate a crime on his behalf.
“Based upon all the materials provided I find that Mark Lamb committed no acts that would be considered criminal under Arizona law,” Miller wrote. “This matter is concluded.”
Lamb served as Pinal County sheriff from 2017 through 2024 and is now running for Congress in Arizona’s 5th Congressional District.
Matthew Holloway is a senior reporter for AZ Free News. Follow him on X for his latest stories, or email tips to Matthew@azfreenews.com.
