The Senate Ethics Committee voted Thursday to investigate allegations that state Sen. Catherine Miranda mishandled petition signatures in the battle over the expansion of the state's school-voucher program.

Such complaints are rare, and usually are reserved for the most serious offenses. They can result in expulsion from the Legislature.

Miranda, D-Phoenix, voted against expanding the Empowerment Scholarship Account program during the legislative session and, after its passage, collected signatures for the effort to refer the expansion to the ballot.

Amy Andrea Celaya, a Gilbert parent who supported ESA expansion, wrote the complaint on letterhead from the group Parents United. She alleges Miranda collected signatures using a petition document that did not check a box designating her as a volunteer signature-gatherer and that someone checked the box after the fact.

ROBERTS:Senate delivers payback for voucher work

The complaint was sent to the Arizona Senate by Chris Perea, a teacher at Gateway Academy and supporter of the school-voucher expansion law who has worked with influential groups pushing for expansion, including Americans for Prosperity and the American Federation for Children.

The complaint included a Twitter photo showing Miranda with the paper with the unchecked box. It was checked when the paper was turned in to the Secretary of State's Office.

Allegations questioned

The complaint alleges Miranda's actions violate state law and so merit an ethics investigation. Knowingly falsifying a petition sheet is a misdemeanor offense.

The Senate Ethics Committee consists of three Republicans and two Democrats. The Republicans voted — with no discussion — to investigate the complaint.

The Republicans decided to first refer the complaint to the Attorney General's Office for investigation and delay their own investigation until that probe is finished.

Sen. Steve Montenegro, R-Litchfield Park, a member of the ethics committee, said the motion doesn't indicate guilt, but starts an investigative process.

"These are clearly just proceedings, questions being asked," he said. "In no way does this reflect the body's prejudice on any decision at all."

FACT CHECK:Do voucher foes want ESA kids in other schools?

Sen. Martin Quezada, D-Phoenix, who is on the committee, noted how unusual it is for someone outside the Legislature to file such a complaint. He said he doesn't think the allegation rises to the level of an ethics complaint.

"If you look at actual evidence that's in the complaint, there's just not much there at all," he said. "This is a witch hunt. This is political retribution against anybody who worked to oppose a law shoved through this Legislature."

Attorney Tom Ryan, who is representing Miranda pro-bono, also questioned why the complaint was being entertained, saying the allegation includes no evidence of intent.

"This is payback. The ultimate result could be expulsion," he said. "This is using a thermonuclear bomb to wipe out a gnat. That's how silly and frivolous this is."

Miranda did not attend the hearing.

TALKING POLITICS: Listen to our Arizona politics podcast, The Gaggle, on Apple Podcasts, SoundCloud, Stitcher or Google Play.

House member faces a complaint

A similar ethics complaint was filed against Rep. Isela Blanc, D-Tempe, in the Arizona House. The House Ethics Committee has not yet taken action on that complaint.

The Secretary of State's Office had already referred the matter to the Attorney General's Office.

Lawmakers haven’t expelled a lawmaker in more than 20 years, although a handful have resigned in the midst of such investigations. The last ethics committee investigations were in 2012.

The Senate committee investigated domestic-violence allegations against former Republican Sen. Scott Bundgaard. The House investigated former Democratic Rep. Daniel Patterson for allegations of domestic violence, as well as numerous allegations of aggressive and dishonest behavior toward other House members.

In both cases, the men were already facing criminal charges related to the domestic-violence allegations. Both resigned before the ethics process concluded.

Related to referendum fight

The Miranda complaint stems from the ongoing battle to keep in place Senate Bill 1431, which the Legislature passed earlier this session and Gov. Doug Ducey signed.

That measure made all 1.1 million Arizona students eligible to apply for the state's school-voucher program, which grants tax dollars to parents for private-school tuition or other education expenses. While broadening eligibility, the bill capped the number of recipients at 30,000 by 2022.

DATABASE:Search Arizona ESA awards in your district

Prior to expansion — which Gov. Doug Ducey and Republican lawmakers narrowly muscled through the Legislature in April — the program had been limited to certain students, including those with special needs, in poor-performing schools or from military families.

Save Our Schools Arizona collected more than 100,000 signatures to refer the measure to the November 2018 ballot.

The American Federation for Children and Americans for Prosperity are fighting in court to keep the voucher-expansion measure in place.

READ MORE:

Will school-voucher expansion save AZ money?

School-voucher opponents clear signature hurdle

Payback for GOP lawmakers who voted no on vouchers?

Oversight of AZ school vouchers 'almost a sham'

Why AZ doesn't know where voucher money goes

AZ school-voucher expansion is on hold. Now what?