(CNN) — Indiana's secretary of state has requested a criminal investigation into the embattled community organizing group ACORN, which is accused of submitting hundreds of bogus voter registration forms in northern Lake County.
The request is based on Secretary of State Todd Rokita's preliminary examination and analysis of 1,438 questionable voter registration applications ACORN submitted in the county, which includes the city of Gary. Rokita, a Republican, has concluded there is "significant, credible evidence" that ACORN violated Indiana and federal law.
"This is a fraud perpetrated on all of the people of Indiana, because fraudulent registrations are the first step in diluting the voice of honest voters and rendering an inaccurate tally on Election Day," Rokita wrote in his request to state and federal law enforcement officials.
In response, ACORN said, "We believe the law requires us to turn in every card."
The group, which is the target of intense GOP attacks, says it flagged questionable registration forms collected by its canvassers. The group has been criticized for submitting phony forms in several states — many of which are considered battlegrounds in next week's presidential election.
But Rokita said ACORN should have turned the documents over to law enforcement, not registrars.
"Complying with the law to submit legitimate applications does not allow ACORN officials to evade the law against knowingly submitting fraudulent applications," Rokita wrote.
ACORN said Rokita "appears to have changed his opinion on this question two weeks before the election."
The group said it detailed its quality control procedures and said that election officials in Lake County had refused the group's documentation flagging applications the group considered questionable and refused to meet with ACORN to discuss how to handle the applications ACORN had flagged. It also said it looked forward to cooperating with Indiana authorities in prosecuting employees "who have defrauded us" by filing faked forms.
ACORN's registration activities in Lake County hit the headlines amid a wave of press reports about questionable voter registration applications submitted by the group in several states.
CNN also recently reported that federal law enforcement officials are reviewing information provided from several state investigations into ACORN's registration activities to determine whether a federal criminal investigation of the group should be opened.
Related: Obama camp calls for special prosecutor in fraud inquiry
In early October, ACORN and Project Vote announced that their extensive voter registration drive in 21 states had yielded 1.3 million registrations. But The New York Times reported last week that ACORN had dramatically reduced its estimate of the number of new voters actually registered during the drive.
Of that 1.3 million, roughly 400,000 were new voters who were not previously registered; another 400,000 were previously registered voters who needed to re-register for various reasons; and another 400,000 involved applications that were unusable because of they are illegible or incomplete, were duplicate applications or were "knowingly bogus," in the words of ACORN spokesman Brian Kettenring.
"The Times piece got something very fundamental wrong," Kettenring said Monday. "We've never claimed that we put 1.3 million voters on the voter rolls. What we've said is we've registered 1.3 million people or when we are being more technically precise, that we have submitted 1.3 million voter registration applications."
Kettenring also said that a yield of 70 percent valid registrations is common for drives like ACORN's. He estimated that the roughly 30 percent of the 1.3 million applications that are not usable break down into 24 percent of the total pool that are duplicates, 5 percent of the total that are illegible or incomplete, and roughly 1.5 percent of the total pool that are "knowingly bogus," as in a registration for "Mickey Mouse."
Echoing prior statements by ACORN, Kettenring also said "what's clear is that there is a coordinated Republican effort to go after, to manufacture a crisis of voter fraud."
"Bogus voter registration applications are not fraud, period," Kettenring said, distinguishing between a fraudulent application and the later act of someone casting a ballot on the basis of a fraudulently procured registration that was submitted and resulted in a tainted registration being placed on the voter rolls. "And, so what you really have is a hysteria about a non-issue," Kettenring added.
Republican presidential candidate John McCain has said ACORN "is now on the verge of maybe perpetrating one of the greatest frauds in voter history in this country, maybe destroying the fabric of democracy." And he has challenged Democratic nominee Barack Obama's to explain his ties to the group.
The Obama campaign maintains that it has never paid ACORN or any of its affiliates to register voters on the campaign's behalf and that the campaign has its own voter registration effort that is problem-free.
"We register our own voters under our own standards and we do so successfully," Obama campaign general counsel Bob Bauer said during a conference call with reporters in mid-October.
–CNN's Drew Griffin and Kathleen Johnston contributed to this report.