Missing Palo Alto couple: Possible lead in search now called recovery mission

MARIN COUNTY, Calif. (KGO) -- As a Coast Guard helicopter makes several low passes over Tomales Bay on Thursday afternoon, the search and rescue effort for a missing Palo Alto couple has turned into a search and recovery mission.

RELATED: Missing Palo Alto couple: Crews come up empty in leads after searching Tomales Bay

Marin County Sheriff's Office says they received four "independent alerts from Cadaver K9 teams" near Shell Beach along Tomales Bay.

In a statement issued by the Marin County Sheriff's Office, they write: "We've worked tirelessly combing through all leads and areas surrounding the cottage they were vacationing at and are now calling this a recovery mission. We have been in close contact with family and will continue to search for Carol and Ian. Our thoughts are with the Kiparsky and Irwin family during this difficult time.

Carol Kiparsky, 77, and Ian Irwin, 72, were on a hiking getaway and staying at an Airbnb cottage in Inverness. Family members they last heard from the couple on Friday, but the Airbnb owner called police when the couple didn't check out as scheduled on Saturday.

RELATED: Search expands for missing Palo Alto couple in Marin County

On Sunday, the Marin County Sheriff's Office began searching for the couple, joined by more than 100 search and rescue volunteers.