SAN FRANCISCO - Volunteers spread out across the city Thursday night to tally how many homeless people call San Francisco home.
The effort will be the second homeless count by Mayor Willie Brown's Office of Homelessness. The first, conducted in April with about 100 volunteers, concluded that 3,610 people live on city streets.
But city officials believe they undercounted by at least 15 to 20 percent, and want to get a more accurate number.
After Brown and Supervisor Gavin Newsom kick off the event, teams of volunteers will begin canvassing the city. They are scheduled to return by midnight.
This time, unlike the April count, the geographic boundaries of the city's new supervisory districts will be used to count the homeless, Brown spokesman P.J. Johnston said.
The purpose of the count is to assist in short-term and long-term planning for the city's homeless services, said George Smith, director of the city's office of homelessness. He said it will become a semiannual event that will yield accurate numbers within two years.
A homeless advocacy group, the Coalition on Homelessness, puts the number as high as 14,000 people - more than four times the mayor's last count.