NEW ULM, Minn. (AP) – Authorities in Minnesota said the search for a woman and her sick 13-year-old son remains focused in southern California and Mexico.

The Brown County sheriff’s department said Sunday it is continuing to look for Daniel Hauser, who has Hodgkin’s lymphoma, and his mother Colleen, who is refusing to allow chemotherapy treatment for her son.

They were expected in court Tuesday. But The FBI says they left their home in Sleepy Eye, Minn., that day for Los Angeles.

Doctors said Daniel has a cancerous tumor growing in his chest that’s likely to kill him without chemotherapy, but his family prefers natural healing methods.

The American Cancer Society estimates there are 35 to 50 clinics in Mexican border towns that attract cancer patients looking for alternative remedies.