Brian Laundrie, a Long Island native, is Gabrielle Petito’s fiancé and a “person of interest” in her disappearance, as he was the last person known to have been with her before she went missing, according to the authorities.
Mr. Laundrie, 23, is himself missing after his parents reported to the authorities that they had not seen him since Sept. 14, several days after he refused to speak with investigators about the whereabouts of Ms. Petito, the authorities said.
He had returned to his house in North Port, Fla., on Sept. 1 in the white Ford van that he and Ms. Petito used in their cross-country journey, which started on July 2.
Mr. Laundrie first met Ms. Petito at Bayport-Blue Point High School on Long Island, according to Ms. Petito’s stepfather, Jim Schmidt.
The couple began their trip in New York, from where they embarked on what was supposed to be a four-month, cross-country journey visiting and camping in national parks, Mr. Schmidt said.
They documented their travels on their Instagram accounts and on YouTube, posting clips that showed them kissing and scaling rocks, scenes back-dropped by blue skies and rugged terrain.
Ten days after Mr. Laundrie returned to Florida, Ms. Petito was declared missing.
Chief Todd Garrison of the North Port Police posted a plea on Twitter addressed to Steven Bertolino, Mr. Laundrie’s lawyer, asking him to arrange a conversation with Mr. Laundrie.
At the time, Mr. Laundrie exercised his constitutional right not to speak with the authorities, Chief Garrison said.
But on Sept. 17, Mr. Laundrie’s parents summoned the police to their home in North Port and told them that they had not seen Mr. Laundrie in three days.
Investigators then started a search for Mr. Laundrie at the Carlton Reserve, a 25,000-acre park about 13 miles from North Port, and where police said his family believes he traveled to. As of Sunday night, there were no reports from police that he had been found.