The Colorado Secretary of State’s office says most of the voters it’s checked against a federal database are citizens and legally registered to vote. But the office is unsure about the status of about 170 voters and wants those people to prove their citizenship. CPR’s Pat Mack reports that process is drawing criticism.

Here is a transcript of Pat's report:

Reporter Pat Mack: The Secretary of State’s office mailed letters to about 3,900 voters in mid-August asking for confirmation of citizenship.  The letters went to people who'd gotten  driver’s licenses with  non-citizen IDs and then appeared on voter rolls. For 2,500 of them, the state didn't have enough data to run their names through a federal database. Those people will be removed from the rolls only if they voluntarily admit to being registered illegally. But 1,400 voters did appear in the database, and 88% turned out to be citizens. The database was unclear on the remaining 12%. Those voters will have to provide proof of citizenship or be dropped from the rolls, according to a new rule the Secretary of State has proposed. At a public meeting yesterday Martha Tierney, an attorney for the state Democratic Party, said it's wrong to spend staff time verifying citizenship for a tiny fraction of voters.

Martha Tierney: This is a witch hunt, and you should be embarrassed that you are going down this road.

Reporter: But Deputy Secretary of State Suzanne Staiert said some non-citizens have received mail ballots, voted and inadvertently committed a felony.  That prevents them from ever becoming citizens.

Suzanne Staiert: Do we have no obligation to notice those people about what they could be walking into in a few weeks?

Reporter: State Sen. Pat Steadman said county clerks have the power to decide voter registration issues, not the Secretary of State. But Staiert said many clerks have asked her office to deal with citizenship questions. The comment period on the proposed rule ended at midnight. The office says it will finalize the rule "soon."