Erik Lippmann was reported missing on Wednesday after apparently leaving his home in the 1200 block of Seabright Avenue at about 2 a.m. that day, according to police.
Lippmann is autistic and is considered at-risk, police said. On Thursday, authorities received a call of a sighting of Lippmann near the intersection of Soquel Avenue and Morrissey Boulevard.
A search and rescue team from the Santa Cruz County Sheriff's Office was sent to the area, but the team did not find him after a search that lasted for a day and a half, police said.
Lippmann travels by foot and has been known to frequent the Capitola Mall and Pacific Avenue areas, according to police.
He is described as a white man who is 5 feet 7 inches tall, 152 pounds, and has hazel eyes and brown hair. It is believed that he is wearing a T-shirt, possibly with cartoon characters on it, pants, and slip-on shoes.
Anyone who sees or had contact with Lippmann is urged to call 911.