An Inverness Park psychiatrist has been missing since early June, without any clues to his disappearance except for an abandoned car found in a beach parking lot. John Deri, a 63-year-old who had lived on Drakes View Drive for the past year and for two decades prior in Stinson Beach, was first reported missing by his wife, Lucy Salter Deri, at 7:12 p.m. on June 3.

When she left in the morning, her husband had been in bed. Ms. Deri made plans to meet him at his office in Mill Valley around 3 p.m., but as the afternoon hours stretched into evening without word from her husband, she began to worry and returned home. She found his cell phone and the dog but no indication of where he had gone. (She did not respond to a request for comment.)

Mr. Deri’s car—a brand-new 2013 B.M.W., black in color—was located the next day by park rangers at North Beach, “known to be a hazardous area,” said Lt. Doug Pittman, the sheriff’s public information officer. “We searched with the hope of finding him until we felt that it was prudent to go ahead and suspend the investigation,” he said. “We’ve tracked his financial records, but there hasn’t been any activity. It’s still a missing persons case, but we don’t have anything further we can follow up on at this point.”

Mr. Deri’s brother Peter Deri flew in from New York City over the weekend to follow up on the case with the sheriff and park rangers. “It’s agonizing. It’s torture not to know what happened,” he said.

John was raised in Manhattan, the son of a Hungarian-trained cellist and Hungarian-trained psychoanalyst. After he graduated from Columbia’s medical school, he came to University of California, San Francisco, to complete his residency in neurosurgery but soon switched to psychiatry.

An Iron Man athlete, he lived for nature and couldn’t resist West Marin’s open trails for hiking and biking. He also took an intense interest in Taoism and Tibetan Buddhism, traveling to see the Dalai Lama when he spoke, no matter if it was San Francisco or Bloomington, Indiana.

“My brother wanted to have an enormous impact on humanity. People would Facebook message him, and I swear he must have answered every one of them,” said Peter, who is also a psychiatrist. “He wanted people to see what was worthwhile in life, wanted them to overcome adversity, take agency over their life.”

Mr. Deri would be 64 years old next month.