The Rev. Al Sharpton is contributing $5,000 to the reward fund for an autistic teenager who has been missing since Oct. 4 when he walked out of his New York City school.
Family members of 14-year-old Avonte Oquendo joined Sharpton at his Harlem headquarters on Saturday. They thanked New Yorkers for their support but said more needs to be done.
The boy's father, Daniel Oquendo Sr., said a search party would set out later Saturday from a tent in front of Avonte's school in Long Island City, Queens.
Dozens of volunteers mobilized in Central Park earlier in the day, breaking up into four groups to search every quadrant of the park.
He asked everyone to keep their eyes open for Avonte and to "keep praying for us."
Sharpton said his National Action Network would help.
The reward for Avonte's safe return was up to $89,500 as of Saturday, including Sharpton's donation.
There have been no verified sightings of Avonte since he went missing.
--Checkey Beckford contributed reporting