PHOENIX (AP) — The Arizona Attorney General's Office said Tuesday it won't prosecute former state House speaker David Gowan following a fraud investigation into expense reimbursements.

A memo detailing the investigation said it found numerous accountability shortcomings in House of Representatives expense-reimbursement procedures and reporting shortcuts by Gowan but a lack of clear-cut violations involving criminal intent by the Republican from Sierra Vista.

Gowan requested the investigation after the Arizona Capitol Times reported on Gowan's use of state cars, apparent mileage reimbursements while driving a state car and requests for daily per diem pay while not doing state business.

Some of the travel involved use of a state vehicle for trips outside his legislative district but in a largely rural congressional district where he was unsuccessfully seeking a congressional seat.

"The investigation has shown that there was substantial disregard for determining whether state funds for per diem, mileage and official travel were paid pursuant to proper authority, acts which could be potential felony violations" of a state law on use of public money, Assistant Attorney General Todd Lawson wrote in the memo. "However, it appears that the violations were not undertaken knowingly or intentionally but were instead attributable to negligence — meaning that criminal charges could not be proven in court."

Gowan previously denied doing anything improper, but he repaid $12,000 to fix errors that he said a review found in his expense requests.

In a statement Tuesday, Gowan said he was "glad to finally put to rest this process."

He added that the decision by the Attorney General's Office "represents the end of a long and exhaustive process that began when I asked for a complete review of actions taken by my office. After more than a year, countless interviews and an in-depth review of reams of documents, their finding that mistakes were made but any errors were unintentional and that no laws were broken is both predictable and welcome."

Before leaving the Legislature in January when his term expired, Gowan in December created a political committee to seek a state Senate seat in 2018.