Marin County's gun buyback program has become a victim of its own success.

During its first-ever gun buyback event on Tuesday, the county collected 827 guns and more than 1,500 rounds of ammunition, most of it from Marin County residents, according to the district attorney's office, which organized the event.

Those turning in guns were given $200 for semi-automatic handguns or long guns, and $100 for other guns. But the $43,000 in cash that was available to those surrendering firearms was depleted within 90 minutes.

When the cash ran out, participants were given vouchers that they were told they could redeem within 30 days. Marin County District Attorney Ed Berberian said $70,000 in vouchers was distributed.

However, it now appears those with vouchers might not be paid unless the county receives more donations for its buyback program, Berberian said Thursday.

A second gun buyback event is scheduled for Monday at the Mill Valley Police Department, but Berberian said people surrendering guns there will be told they won't receive any money. The buyback is scheduled for 11 a.m. to 3 p.m.

Initially, there were scheduled to be two collection sites on Monday but the county has since cancelled one that would have been in San Rafael.

Berberian said the people who received vouchers on Tuesday were told that the vouchers were not guaranteed, and many said they didn't care.

Anyone who wants to make a tax deductible donation to cover the vouchers issued in the buyback program can mail a check to the Marin County District Attorney's Office, Attention Gun Buy Back Program, Room 130, 3501 Civic Center Drive, San Rafael, Calif., 94903.

A tax identification number will be issued to contributors, Berberian said.