Officials said Paul Flores was detained and released Wednesday morning by San Luis Obispo deputies and the FBI.
Authorities served search warrants Wednesday in San Pedro, San Luis Obispo County and Washington state.
In a statement, the San Luis Obispo County Sheriff's Office said it disclosed the development "due to the high-profile nature of the investigation into the disappearance and whereabouts of Kristin Smart and to avoid the dissemination of misinformation."
The search warrants were "limited in scope and sealed by the court," the news release said, adding that additional information would not be immediately provided.
September 2016: FBI renews search for Cal Poly San Luis Obispo student missing for 20 years
News video from AIR7 HD showed FBI personnel and Los Angeles County sheriff's deputies outside the San Pedro location in a residential neighborhood Wednesday morning.
Smart was last seen returning to her California Polytechnic State University dormitory from an off-campus party on May 25, 1996.
Paul Flores released and is back home. https://t.co/ikcpNh5B5o
— Miriam Hernandez (@abc7miriam) February 5, 2020
COLD CASE disappearance. Search underway in San Pedro for evidence in Kristin Smart who vanished from San Luis Obispo in 1996. A classmate Paul Flores is person of interest says SLO Sheriff.More at 11. pic.twitter.com/tf7qREcQaz
— Miriam Hernandez (@abc7miriam) February 5, 2020