The state will prosecute any cases of suspected fraud following a news report showing votes were cast in the names of dead people, Colorado Secretary of State Wayne Williams said Friday.

Williams said he is working with Colorado county clerks and district attorneys to root out voter fraud. In a report Thursday, CBS4 found several cases of records showing votes being cast by people who had died years earlier.

“Our office is working to ensure all such incidents are prosecuted and that laws and rules are adjusted to make vote fraud as difficult as possible,” Williams said in a release late Thursday. Williams’ office also is working with county clerks to streamline the process required to delete deceased voters from voting rolls.

To erase voting records, counties use certain pieces of identification to verify the identity of the deceased, Williams told The Denver Post on Friday. If “the driver’s license, address is the same, date of birth is the same, but you have a different last name, it’s highly possible you might be the same person,” Williams said, but right now the law doesn’t allow counties to erase voters without matching information.

Sara Sosa was a regular voter in El Paso County elections, both state and federal. She voted in 2010, 2011, 2012 and 2013. CBS4 found she died in 2009.

Records showed Sosa and three other Colorado voters casting ballots after they died. Williams’ office found that another 78 dead Colorado residents were still actively registered to vote after CBS4 contacted them.

Counties receive a monthly list of voters who have died recently from the Department of Public Health and Environment and the Social Security Administration. They compare this with several other pieces of identification and the self-reported voter registration before deleting voters from their rolls.

Prior to 2012, when Colorado joined Electronic Information Registration Center, counties did not receive the monthly Social Security Death Index. After El Paso started receiving the list, officials were able to delete 448 registered deceased voters from their rolls.

Alton Dillard, spokesman for the Denver Elections Division, said that after the investigation, the division looked into its records and found two instances of voter fraud among Denver voters. One happened about a decade ago, possibly due to the committee switching systems. Another, he said, was caught and prosecuted years ago.

Every election, county clerks hand over hundreds of cases of potential voter fraud to the attorney general. Often the issue will be born out of an unintentional discrepancy between self provided information and what the government has on file. Williams said that he hopes this incident will encourage lawmakers to “look at potential legislation to ask: does it make sense to broaden criteria to allow us to make a decision even if the name may be different?”

The El Paso County District Attorney is currently investigating the Sosa cases, but these kinds of cases are difficult to prosecute. Unless someone comes forward to provide testimony, there’s little hard evidence to present, Broerman explained. “If our laws are not strong enough to prosecute this case, I don’t know what can be prosecuted,” he said.