Winker said tips have been flowing in since Tibbetts was last seen July 18 while going for a run in Brooklyn.
It's been more than two weeks since Dalton Jack last saw or heard from his girlfriend, 20-year-old Mollie Tibbetts, before she mysteriously vanished in a rural Iowa town.
Investigators say they have concluded that a woman spotted in northwest Missouri was not Tibbetts.
"The Kearney Missouri Police Department did respond to a possible sighting on 7-26-2018 at a truck stop within our jurisdiction", local police said in an official statement.
The Mollie Tibbetts search turned up a red shirt near an Iowa pig farm this week and, while it is not clear whose shirt it was, Fox News reported confirming that the missing college student worked at a day care where the uniform includes red shirts.
Investigators have said previously that they were confident on Tibbetts' digital footprint, but they did not release any information as to where that was.
"We believe that Mollie is still alive and if someone has abducted her we plead with you [to let her go]", Tibbetts' mother, Laura Calderwood, said.
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The family also praised law enforcement efforts as well as national and worldwide media coverage that has kept Tibbetts' disappearance in the public consciousness.
Calderwood said she feels her daughter's presence every day.
"You obviously care for Mollie and, if you're holding her, you've made a huge mistake", he said. "It is our greatest hope that if someone has her, that they would just release her and claim that money we have raised for her freedom".
"At this point, we don't know her exact whereabouts but we continue to look". She said the money would be paid to anyone who provides information to Crime Stoppers of Central Iowa that leads to Tibbetts' safety.
Authorities have yet to give an official timeline; but police have been combing through information from Tibbetts' Fitbit, which she always wore, as well as her cellphone and social media accounts.
"The first night she went missing, I was distraught", Calderwood told CNN affiliate KCCI in Des Moines.