By Brian Maass and Mark Ackerman

COLORADO SPRINGS, Colo. (CBS4) – The El Paso County District Attorney has charged a Colorado Springs woman with six counts of felony forgery, accusing her of repeatedly forging her deceased parents signatures on mail-in ballots.

The charges against Sarilu Sosa-Sanchez, 59, follow a CBS4 investigation last fall into ballots being cast in the name of dead voters.

Sosa-Sanchez’s mother, Sara, died in 2009. She was a registered Republican. But CBS4 found ballots were cast in her name in general elections in 2010, 2011, 2012 and 2013. Miguel Sosa — also a registered Republican — died in 2008 but records uncovered in the CBS4 investigation showed a vote cast in his name a full year after his death.

The broadcast report prompted El Paso County authorities to launch a criminal investigation, which led to the forgery charges. Sarilu Sosa- Sanchez is due to appear in court for the first time Thursday.

“While voter fraud is rare, a lax approach to prosecuting voter fraud can lead to additional and unacceptable attempts to cheat the system,” said El Paso County Clerk and Recorder Chuck Broerman.

“Every individual who votes legally has his or her voice diminished by voter fraud.”

When CBS4 contacted Sosa-Sanchez at her Colorado Springs home last fall, she declined to admit who she was or the alleged forgeries.

“You can believe anything you want, it doesn’t mean that’s the truth,” she said. “Go talk to somebody else. I don’t even know what you are talking about.”

The charges come as a voter integrity commission convened by President Donald Trump has begun asking states for detailed voter information. The commission has been tasked with investigating improper and fraudulent voting, which most experts contend does not happen on a widespread basis.

Appearing on CBS4 Tuesday morning, Colorado Secretary of State Wayne Williams acknowledged the CBS4 investigation has revealed scattered cases of ballots being cast from the grave, but he reiterated it was not a widespread problem.

“I have not seen any evidence to indicate voter fraud on the level described in the millions. I have seen instances, we are following up on those and Colorado will investigate and prosecute,” he said.

CBS4 Investigator Brian Maass has been with the station more than 30 years uncovering waste, fraud and corruption. Follow him on Twitter @Briancbs4.

Mark Ackerman is a Special Projects Producer at CBS4. Follow him on Twitter @ackermanmark