Todd Rusten was last seen at his home in the Heaven's Gate sober living environment about 9 a.m. on June 9. His mother reported him missing two days later.
His mother said Rusten is able to care for himself, but that having Asperger's syndrome sometimes prevents him from making good judgments, according to Garcia.
Rusten's mother said he is also addicted to inhaling refrigerant, a chemical that circulates in an air conditioning system, Garcia said.
Rusten has been in and out of jail. He lives at the Heaven's Gate community as ordered through a court drug program, Garcia said.
A blue mountain bike he has been known to ride in creek areas like the Guadalupe Creek in downtown San Jose is also missing, Garcia said.
Detectives have checked that creek and others around the city, but have found no trace of Rusten or his bike. However, Garcia said there is nothing suspicious about Rusten's disappearance.
Rusten is 5 feet 9 inches tall, about 185 pounds, and has brown hair and brown eyes.
