“Your account system is a mystery,” Centorino told him.

Further complicating matters: Rivera raised as much as $175,000 in donations for his campaigns to be a committeeman with the state Republican Party. Unlike campaign donations for legislative offices, committeeman money was largely unregulated, allowing Rivera to spend it on any expense deemed even vaguely political, Band argued.

“As a state committeeman, if he wanted to take his campaign crew to a strip club, bar, he could,” Band told the investigators, according to the meeting notes. “He may be a lousy bookkeeper, we can agree. But criminal, we can satisfy that he didn’t.”

(Band later complained in a letter that the meeting notes were not an accurate reflection of the meeting.)

The FDLE’s Lycett spent the next several weeks examining the restaurant receipts, hotel bills and other expenses that Rivera considered political. Lycett flagged about $1,700 in charges that Rivera counted as both political expenses and legislative costs billed to the state, records show.Another $8,400 in political expenses claimed by Rivera were paid on days that Rivera received a “per diem” from the state for traveling on state business, FDLE records show.

A thorny law

By that time, however, prosecutors appeared ready to drop the criminal case altogether.

The attorneys ultimately concluded that they could not charge Rivera with felony theft for double-billing the state, because state law allows only misdemeanor charges for abusing state travel vouchers — with a short two-year statute of limitations that barred prosecution for many transactions. Any attempt to charge Rivera with felony theft, the prosecutors concluded, would likely get thrown out of court, according to a memo closing the case.

In his campaign statement, Rivera said per diem expenses were approved by state officials, and said any accusations of double-billing were “patently false.”

Prosecutors also considered a racketeering case based on campaign misspending, but ultimately determined that would be a novel prosecution never seen before. “Plainly stated, we were unable to find any support under Florida law for this theory,” the prosecutors wrote.

On Oct. 12, Arrojo e-mailed Rivera’s lawyer a proposal: If Rivera admitted to violations of state election laws, the prosecutors were willing to forgo criminal charges. “We are pretty much done with our review of this matter,” Arrojo wrote.

In his statement to The Herald, Rivera said he “summarily rejected” the offer.

“Knowing I didn’t do anything wrong, I told them I would see them in court,” Rivera said in a follow-up phone interview. “I will never allow myself to be intimidated or extorted by anyone, including the state attorney.”

Meanwhile, communication between the FDLE agents and the Miami-Dade prosecutors slowed to a trickle.

On Oct. 26 — two weeks after the settlement offer to Rivera — Rundle told Bailey, the FDLE commissioner, that her staff was “still reviewing the facts” and had not yet decided whether to charge Rivera, FDLE records show.

A week later, Bailey wrote Rundle a letter urging her to expedite the case, but the state attorney did not respond for more than two months. Rundle later told Bailey the letter was misplaced over the holidays.

On March 21, an FDLE supervisor, Cindy Sanz, asked Arrojo for an update but received no response. Two weeks later, she wrote again to the prosecutor: “Since I have not heard from you, I will presume that no progress has been made,” Sanz wrote. “As you and Ms. Rundle have already indicated that your office does not intend to pursue prosecution of Mr. Rivera, FDLE has now closed our investigation.”

Arrojo then urged the FDLE not to release any information to the press, arguing that the investigation was “still in the end stage,” e-mail records show. But an FDLE lawyer said it was difficult to consider the case an active investigation, making the records inaccessible to the public, because “nothing is happening.”On April 18, the FDLE lawyer informed Rundle’s office that the FDLE was releasing records of the investigation to reporters asking about the case. Rundle’s office formally closed the investigation that very day, releasing its 16-page memo explaining why no charges were filed.

“It would greatly aid prosecutors in these types of inquiries and provide clearer guidance to candidates if the law was revised,” Arrojo and Rosen wrote in wrapping up the 18-month probe. “We have been confronted with the fact that an elected official over a period of many years may essentially live off a combination of [political] contributions… while avoiding penal sanction.”