The first phantom absentee ballot request hit the Miami-Dade elections website at 9:11 p.m. Saturday, July 7.

The next one came at 9:14. Then 9:17. 9:22. 9:24. 9:25.

Within 2½ weeks, 2,552 online requests arrived from voters who had not applied for absentee ballots. They streamed in much too quickly for real people to be filling them out. They originated from only a handful of Internet Protocol addresses. And they were not random.

It had all the appearances of a political dirty trick, a high-tech effort by an unknown hacker to sway three key Aug. 14 primary elections, a Miami Herald investigation has found.

The plot failed. The elections department’s software flagged the requests as suspicious. The ballots weren’t sent out.

But who was behind it? And next time, would a more skilled hacker be able to rig an election?

Six months and a grand-jury probe later, there still are few answers about the phantom requests, which targeted Democratic voters in a congressional district and Republican voters in two Florida House districts.

The foreman of that grand jury, whose report made public the existence of the phantom requests, said jurors were eager to learn if a candidate or political consultant had succeeded in manipulating the voting system. But they didn’t get any answers.

“We were like, ‘Why didn’t anyone do something about it?’ ” foreman Jeffrey Pankey said.

Read the story here. View a map of the phantom requests here.