This election cycle, a number of Republican politicians, led by President Trump, have claimed that mail-in voting is open to widespread fraud and abuse. Democrats, meanwhile, have called on voters to use the system—in states that allow it—to avoid the potential of long lines and other issues related to the coronavirus pandemic on Election Day.

While electoral fraud does occur, and does occur with voting by mail, it is extremely rare and does not affect outcomes. According to a 2007 report by the bipartisan Brennan Center for Justice, which reviewed past elections, voter impersonation occurs at rates somewhere between 0.0003% and 0.0025%, and most incidences are due to clerical errors or bad data matching practices. A 2014 investigation published in the Washington Post found 31 cases of credible voter impersonation between 2000 and 2014, out of more than 1 billion votes cast.

A recent case of voter impersonation in Florida highlights how secure the system is. On Friday, the sheriff of Manatee County, on the state’s western coast, announced the arrest of a 62-year-old widower who had requested a mail-in ballot for his deceased wife. The attempt was caught by the county’s election supervisors when the wife’s handwriting style on the absentee ballot request did not match that of her voter registration. No ballot was mailed out. The man was arrested and released on $1,500 bail.

Nearly 4 million mail-in ballots have been requested in Florida, per the New York Times, making this a 0.000025% instance.

We don’t know the man’s party affiliation or whether he would have turned the ballot in. But we do know why he did it: According to the Sarasota Herald-Tribune, the man told sheriff’s deputies that he was “testing the system to see if it worked.” It did.