Salt Lake City authorities identified the person arrested as Ayoola Ajayi, 31. He will be charged with aggravated murder, kidnapping and desecration of a body in her death.
Neighbors reported they saw Ajayi burning something in his backyard with gasoline on June 17 and 18, police said. An investigation of the property found an area that had been freshly dug — the same area that neighbors reported seeing the fire.
Investigators found charred material that were determined to be human female tissue that matched Lueck's DNA. They also found several other charred items that were consistent with Lueck's personal items.
Lueck, 23, had been missing since June 17. Her parents last heard from her when she texted them around 2 a.m. that morning and informed them she had made it safely back to Salt Lake City on a flight.
The University of Utah student then grabbed a Lyft, which she took to meet a man near Hatch Park. She did not look distressed when she got into the man’s car around 3 a.m., the driver told police. That man, police said, was Ajayi.
It's not clear whether Ajayi has an attorney.
A contractor told Fox News that he was approached by an individual who owns the home searched, now believed to be Ajayi, to build a soundproof room in the home.
“He slowly added on other requests, like building a secret door and adding hooks to the wall,” Brian Wolf said.
Wolf said that the person also asked the construction be completed “before his girlfriend got back into town.”
"Weirded out" by the request, Wolf turned the person down, he said.
On Wednesday, friends of Lueck spotted activity on her Instagram account and reported it to cops. A page called “fatherless,” which has 47,000 followers, was liked from Lueck’s personal Instagram around noon, according to activity screenshot by Lueck's friends.
Police had initially said they did not believe Lueck was in danger, and on Wednesday, they maintained the case was still a missing persons investigation.
After Lueck's initial disappearance, it was reported that the University of Utah student was dating multiple people through online dating sites and apps, according to The Daily Mail. She was also a self-proclaimed “sugar baby,” according to a post she wrote in a private Facebook group months ago.
“Try tinder and be blunt about it. Mine says 'I want a SD/SB relationship with a real connection.' If [they] don't know what a SD/SB is, tell them bluntly sugar daddy and sugar baby. But if they don't know, they aren't really worth your time," read one of Lueck's comments on the page.
Police said earlier this week that they were looking into Lueck’s social media and dating profiles.