"There have been credible sightings of Mitrice Richardson," said L.A. County Sheriff's Spokesman Steve Whitmore. "It is by no means definitive, but investigators are there, and the reason why they're doing the press conference tomorrow is they are seeking the public's help to solidify this. Investigators want to prove that it is in fact true, that she is alive and in Las Vegas, or to prove, in fact, that she is not."
Richardson, a Cal State Fullerton graduate, was arrested in a Malibu restaurant in September 2009 after she couldn't pay her bill.
Her car was impounded and she was detained overnight. She was released in the early morning hours of Sept. 17 without ID or a phone. Her phone and purse remained in her impounded car.
Restaurant patrons had described as Richardson as acting strangely. It's believed Richardson may have been suffering from a bipolar-disorder episode.
The Los Angeles County Sheriff's Dept. was criticized for releasing a mentally unstable woman without identification or means of communication so far away from her home.
Richardson's parents filed a lawsuit against the department for negligence.
Richardson's father said he saw someone who looked like his daughter in Las Vegas months ago.
"I know a lot of people feel like I should be elated," said Michael Richardson, Mitrice's father. "But I'm pretty much disgusted because I notified the sheriff's [office] of a personal sighting, a possible sighting, of Mitrice in Las Vegas in January of this year. By me personally, when I was out there. So I just think what their efforts are doing now is a reaction based on the filing of a lawsuit yesterday."
Latice Sutton, Mitrice's mother, said she's worried that her daughter is being held against her will.
"Someone has taken my daughter across state lines, and the FBI, I want to know, where are they?" Sutton said.
Authorities are hoping that Mitrice will be listening during Thursday's news conference in Las Vegas to their message:
"Ms. Richardson, you're not in trouble," said Whitmore. "You're not subject to arrest. People are just concerned about you, and we'd like you to contact us."