Tibbett's family is offering a $172,000 reward for information that will lead authorities to her, Time reported.
Her family and friends are posting flyers and talking to the public and the media about a new reward fund for information on the whereabouts of the 20-year-old.
Jack, also 20, said he doesn't believe there's a chance Tibbetts would have left on her own accord. The Iowa Division of Criminal Investigation has said that Tibbetts was last seen jogging in her nearby hometown of Brooklyn, Iowa.
Over two weeks since her shock disappearance, the family of missing university student Molly Tibbetts have not given up hope. "And Mollie was an incredibly strong young woman and I don't know that I have the strength in me and Mollie is lending me her strength every day and every night", she added. At the press conference, her loved ones spoke about what the search has been like.
In an update on August 3, the Iowa Department of Public Safety wrote that "although Mollie has not been located, the investigation into her disappearance has not slowed". Mollie Tibbetts' mother pleaded for anyone who may have abducted her daughter to let her go and said anyone with information on the case can come forward anonymously.
"We exist for the other ones, who for whatever reason would not come and communicate any information to the police, either because they are guilty of something themselves or maybe involved in a crime", Willey said. Her disappearance has gained national attention.
The Iowa Department of Public Safety said that her last known article of clothing is believed to be dark-colored running shorts, and a pink sports top and running shoes, color unknown.
"It's one thing to say, 'You know what, call us and we'll protect your identity, won't tell anybody".