SEATTLE - As the counting winds down in the Seattle mayoral race, controversy may heat up as officials deal with a vandalized ballot box and 5,700 ballots with signatures that don't match those on file.

Either problem could affect the vote totals, and that could cause headaches in a close election like that between Mike McGinn and Joe Mallahan. Friday's update shows McGinn with 1,209 votes more than Mallahan with some 25,000 ballots still to count.

To solve the problem of mismatched signatures, King County elections officials say they are trying to contact all 5,700 people whose signatures don't match those on file. If they can't, the thousands of ballots could go uncounted.

The vandalized ballot lockbox could pose a more intractable problem.

The box, like all the others, was closed by election officials at 8 p.m. on Election Day. But this box was vandalized. Someone tore off the metal seals, which would allow late, illegal ballots to be dropped in.

Megan Copperfield of King County Elections said the lockbox was broken into sometime Tuesday night. But there are no surveillance cameras that show exactly when orhow it happened.

"There are twenty two cameras around election headquarters. No one thought drop boxes would be a target. They were out of camera range," Copperfield said.

Inside the vandalized box were 860 ballots. But there is no way to know how many of them, if any, were dropped in after the voting deadline had passed - and therefore illegal.

King County Elections Director Sherill Huff said the vast majority of ballots in the box are legitimate. But officials have know way of knowing exactly which ones are legal and which are illegal.

That leaves the county in a bind. If the ballots are tossed, thousands of legal voters will be disenfranchised. If they are counted, it could be the stuff of lawsuits.

King County officials are making a promise that this will never happen again. From now on, when a ballot drop box is closed, an election worker or workers will have collected all the ballots from the box.

The final decision on whether to count the 860 ballots in the drop box will be made by the county canvassing board.