Police investigating the baffling disappearance of University of Utah student Mackenzie Lueck released images from the last known footage of her Tuesday and pleaded for the public's help. Police said surveillance cameras captured the 23-year-old at Salt Lake City International Airport between 2:09am and 2:40am on June 17, Fox reports. She took a Lyft to a park in North Salt Lake, where she met an unknown person in a vehicle around 3am, police say. She has not been heard from since. "Over the course of approximately 31 minutes, Mackenzie walked from the jetway to catch the Lyft with a quick stop to pick up her luggage," Salt Lake City Assistant Police Chief Tim Doubt told reporters. "She did not appear to talk to anyone in the airport."
Doubt said police had been unable to determine the identity of the person Lueck met, or even if it was a man or a woman, the Salt Lake Tribune reports. A family spokesperson tells CBS that police are investigating Lueck's use of dating apps and are trying to find out whether she had any secret phones or social media accounts. Doubt said Salt Lake City police have had three interactions with Lueck: "A moving violation in 2015, an assault a year ago, and found property six months ago." He didn't say whether Lueck was a witness, victim, or suspect in the assault, but told reporters that there is "no indication that any of these interactions are connected with her disappearance and all of those cases are resolved." Doubt urged anybody with information to call the tip line at 801-799-4420. He said 125 tips have already been received. (Read more Utah stories.)