On the Friday of Memorial Day weekend in 1996, Kristin Smart — a California Polytechnic State University, San Luis Obispo, freshman — went missing after attending an off-campus party.
More than 20 years later, the family of the upbeat, athletic 19-year-old from Stockton, California, is still looking for answers.
On Wednesday, Paul Flores, the longtime person of interest in the case, was briefly detained before being released. Flores, now 43, was a classmate of Smart’s and was the last known person to see her alive after volunteering to walk her home in her inebriated state from the party, police have said.
In mid-January, the case came back in the headlines after her mother, Denise Smart, said the Federal Bureau of Investigation had recently contacted her about her daughter’s case, telling her to stay tuned for some news — but that the news would be something unexpected.
But in a subsequent statement released days later, the Smart family said they’d actually been in contact with a retired FBI agent, and both the family and local authorities said no announcement was imminent.
Since then, however, there has been activity in the case. In addition to briefly detaining Flores, police searched his home as well as that of his parents.
In late January, the sheriff’s office said evidence in their ongoing investigation includes two trucks that belonged at the time to family members of , a longtime person of interest in the case.
Here are five things to know about Smart’s baffling disappearance:
1. Flores Was Briefly Taken into Custody
Authorities also searched Flores’ home in San Pedro and were seen leaving the home of Flores’ parents in Arroyo Grande with a computer, a brown paper bag, a storage bin and other pieces of evidence, The Tribune reported.
The sheriff’s office did not immediately respond to PEOPLE’s request for comment, but it said in a press release on Wednesday that it had “served search warrants for specific items of evidence inside four separate locations in California and Washington.”
“Two of those locations are in San Luis Obispo County, one location is in Los Angeles County and one location is in Washington State,” the release stated.
2. Smart Was Last Seen Heading Back to Her Dorm After a Party
With classes finished before the long Memorial Day weekend, Smart called her parents on Friday, May 24, 1996, and left a message telling them that she and some friends were heading to a party at 8 p.m. that night. While she told her parents to call her before she left, she never spoke to them.
Smart ended up attending an off-campus party, where she got drunk and passed out on a neighbor’s lawn, according to witnesses.
3. Smart Was Last Seen with Flores — Who Has Long Been a ‘Person of Interest’
Police have said that two students, including one of Smart’s girlfriends, offered to help her get back to her dorm, since she was unsteady on her feet. While they headed back to Muir Hall, where Smart lived during the school year, Flores volunteered to walk her home, according to police.
No one ever saw Smart again. The next afternoon, when Smart failed to show up for lunch, her friend alerted campus police, which didn’t begin fully investigating her disappearance until that Tuesday, when classes resumed, according to authorities.
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Cipolla, the sheriff’s office spokesman, tells PEOPLE Flores is still considered a person of interest in the case.
4. Flores Has Never Been Charged
After Smart vanished, campus police questioned Flores. When he was asked about a black eye he sported, he told campus police he got hurt in a pickup basketball game, but authorities grew suspicious when one of his friends later told authorities Flores already had the bruise when he showed up to play.
According to The Tribune of San Luis Obispo, he later admitted that was a lie and told authorities he got the bruise fixing his truck before ending the interview.
Later that year, after Flores had returned home for the summer, investigators from the sheriff’s office later searched his dorm room with four cadaver dogs, which keyed in on Flores’s mattress, according to police.
But Flores has never been charged, and in 1996, a grand jury did not indict him.
He has remained mum about the case, invoking his Fifth Amendment right to remain silent when he was deposed in a 2005 wrongful death civil suit brought against him by Smart’s parents, which they subsequently dropped.
PEOPLE has not been able to reach Flores for comment.
In 1998, his attorney told PEOPLE that authorities had no evidence against Flores.
“It’s one thing to have suspicions,” Melvin de la Motte told PEOPLE, “but that doesn’t make up for evidence.”
PEOPLE was unable to reach de la Motte for comment.
5. Smart’s Mom Said Waiting for News Is ‘Anxiety-Producing’ — But Authorities Say No News Is Forthcoming
Denise Smart told the Stockton Record that the retired FBI official, in saying that news was imminent, told her the family “might want to get away for a while.”
However, she said she wasn’t told when she and her family will get any more news.
“I wish I knew when,” Smart told the outlet, “because it’s very anxiety-producing.”
“It’s like, ‘Can you give me the flight plan?’” Smart said. “When is this happening?”
The family’s statement issued after the publication of Denise Smart’s comments seemed to contradict the idea that an announcement on the case was imminent, yet there has been activity in the case since then.
6. Evidence Includes 2 Trucks Once Owned by Flores’ Family: Police
Police announced in late January that their evidence in their ongoing investigation includes two trucks that were owned by Flores’ family in 1996.
The sheriff’s office, when announcing the evidence, did not specify when investigators had acquired the trucks still in their possession.
But since 2011, according to the sheriff’s office, investigators have collected 140 “new items of evidence,” searched nine separate locations, served 18 search warrants, resubmitted 37 pieces of evidence from the investigation’s early stages for more-current DNA testing and conducted 91 face-to-face interviews.
None of it so far has led to Smart’s recovery or a criminal prosecution.
• With reporting by JOHNNY DODD