(KRON) The family of a 73-year-old man who disappeared without a trace Tuesday morning in Oakland believes he may have boarded a BART train minutes after he was last seen.

John Nelson Beck was last seen in the 1300 block of Clay Street, near the Oakland City Center, at around 9 a.m., according to police. Beck had been dropped off and was scheduled to have an appointment but never showed up.

According to Beck’s family, new information from police suggests BART security cameras show Beck boarding a Millbrae-bound train at 9:06 a.m. at the 12th Street Station.

“My father has never gone missing in his life and is not the sort of person to worry us unnecessarily,” Beck daughter, Kate Kigudde, a diplomat with the U.S. State Department in Cyprus, said in a statement.

“Having heard that my father was seen boarding BART in Oakland, it is crucial that police can obtain footage from other stations to see where he alighted. Reports this week that 77 percent of online BART security cameras are non-functioning decoys doesn’t help us in our search, but we are certain the authorities are using all technology available to find my father,” Kigudde said.

Beck does not suffer any medical conditions that would cause him to become disoriented or lose his memory, according to his family.

Beck is a white man with glasses standing 5 feet 11 inches tall. He was last seen wearing navy blue pants with green and blue plaid shirt.