Susan Risenhoover of Camano Island wanted badly to vote for Barack Obama but couldn’t because she wasn’t a registered voter.

So when a ballot arrived in the mail for her son, then living in Texas, she filled it out, signed his name and sent it in.

It never got counted. Island County election officials saw the signature differed from the one on her son’s voter registration card. An investigation ensued and earlier this month Risenhoover pleaded guilty to a felony charge of unqualified person voting.

She is the only person in Island and Snohomish counties — and maybe the entire state — convicted of committing voter fraud in the 2008 general election in which 3 million people participated statewide.

Election officials aren’t surprised it’s the only case as they’ve long insisted voter fraud is a rarity in Washington and happens far less than the public may perceive.

It’s a hard perception to erase, with memories still vivid of 2004 and the accumulation of procedural errors, misplaced ballots and votes cast by felons.

Critics of election officials now worry fraud is more widespread and difficult to prove because voting by mail, the practice in 38 of 39 counties in the state, creates a raft of new opportunities for cheating.

“We’re confident that fraud is not on the rise. We certainly don’t see anything to indicate that,” said Shane Hamlin, the state’s assistant director of elections.

Innumerable improvements including deployment of statewide voter databases improved security, he said. The Island County case shows that auditors and prosecutors “are doing what they can to protect the integrity of elections,” he said.

For Holly Jacobson, director of Seattle-based Voter Action, a national group that works to ensure elections are properly conducted, precinct voting still offers a better chance at deterring fraud.

Voters have their identity checked, their signatures on poll books witnessed and their ballots scanned on-site, she said.

“There are just greater checks and balances with poll voting,” she said.

Since Snohomish County switched to voting-by-mail in 2006, there’s been no surge in wrongdoing, Auditor Carolyn Weikel said.

If people want to cheat, they’ll find a way and “sitting at a table at home with a ballot or putting them in a voting booth is not going to change that behavior,” she said.

“My experience is we find voters are making honest mistakes and are not trying to cheat the system,” she said.

There were a lot of honest mistakes made in the presidential election — clear violations of election rules though not so clear violations of the law.

Weikel’s office referred close to 100 cases to the Prosecuting Attorney’s Office. No charges resulted.

Proving beyond a reasonable doubt that someone willfully committed voter fraud is difficult if there are no witnesses and only the word of the voter to rely upon, authorities said.

In the case of Susan Risenhoover, she didn’t deny any wrongdoing. She told an investigator she knew she couldn’t vote because she wasn’t registered. She admitted to intentionally filling out her son’s ballot and signing his name on it.

She told the investigating sheriff’s detective her son had not given her permission to do what she did. Her son did tell her he “was only mad that Susan had voted for Barack Obama and that he would have voted for John McCain,” according to a court affidavit.

Risenhoover, who had no prior criminal history, was sentenced to five days in jail. A judge converted that to 40 hours of community service.

In Snohomish County, about 50 of what Weikel described as “honest mistakes” involved people voting twice — once by mail and a second time at the touch screen machines set up in several locations around the county.

There were also cases of ballots sent to one person coming back signed by another. Typically this turned out to be one spouse signing for another.

The ballot of an Everett woman came back with her father’s signature.

“I forgot to sign the ballot,” she wrote election officials. “I authorized my dad to sign it for me because I was back in school in Canada and was unable to sign it in time. I’m sorry if I violated any laws. I just wanted my vote to count in the election. I will not do it again.”

There were a number of ballots on which the signature didn’t match that person’s penmanship on their voter registration card.

These did arouse suspicion of someone trying to steal another person’s vote. Upon investigation, in some cases the person’s signature had simply changed. In others, the affected voter didn’t express any concern so authorities presumed it would be tough to prove a crime occurred.

In every case, the auditor sends a letter to the voter seeking an explanation.

“People typically think they’re doing the right thing,” she said. “We tell them they’re not and then they never do it again.”

Reporter Jerry Cornfield: 360-352-8623, jcornfield@heraldnet.com.