Authorities are searching the home of a person of interest in the mysterious case of missing University of Utah student Mackenzie Lueck, police said.
Investigators are also looking to track down a mattress discarded from that house, police said.
Lueck, 23, was last seen in the early hours of June 17. She landed at the Salt Lake City International Airport around 2 a.m., then at 2:40 a.m. she took a Lyft from the airport to Hatch Park in north Salt Lake City, police said.
The Lyft driver told police that an individual met Lueck at the park and the 23-year-old did not appear to be in distress, police said.
The college senior hasn't been seen since.
On Wednesday night police executed one of many warrants in the case and searched the home of someone they've determined to be a person of interest, Salt Lake City Police Chief Mike Brown said at a news conference Thursday.
The homeowner, who has not been named, has spoken with detectives, said Brown. The chief said it is not clear if the person of interest is the same person Lueck met at Hatch Park.
No arrests have been made, Brown said.
On Wednesday night police learned that a mattress and box spring were given away from the home last week, Brown said. Whoever took the mattress and box spring is asked to contact police so investigators can collect them, Brown said.
Multiple items of evidence were collected from the home and are in the process of being analyzed, Brown added.
Lueck had gone home to Southern California for her grandmother's funeral before flying back to Utah on June 17.
Since then, Lueck has missed an exam and was not on her flight to California on June 23.
"I feel very concerned and very worried," her friend Kennedy Stoner told "Good Morning America" earlier this week. "It's out of character for Kenzie to go just off the grid like this. She is very close with her family."
Chief Brown said that having spoken to Lueck's father, "I can feel the heartache and the pain and the suffering in his voice as we spoke."
The Lyft driver and Lyft officials have spoken to police and have cooperated with the investigation, authorities said.
ABC News' Marilyn Heck contributed to this report.