Investigators say missing University of Utah student MacKenzie Lueck has been murdered — and police have arrested a Salt Lake City man they say killed her and burned her body.

Ayoola Ajayi, 31, has been booked into jail on suspicion of aggravated murder, aggravated kidnapping, desecration of a body and obstruction of justice after a SWAT team took him into custody Friday morning at a West Temple apartment complex, said Salt Lake City Police Chief Mike Brown.

“I will not be saying the killer’s name again,” Brown said.

A judge later Friday ordered Ajayi held without bail. As of midafternoon, he had not yet been formally charged.

A man identified only as Lueck’s uncle appeared at Friday’s news conference. He read a brief statement thanking police and others who helped with the investigation.

Lueck, a 23-year-old University of Utah student, has been missing since June 17, when she arrived back in Salt Lake City from California, where she was attending her grandmother’s funeral. She texted her mother when her flight landed about 1:30 a.m. and then ordered a Lyft to Hatch Park in North Salt Lake, nearly 9 miles from her home near Trolley Square, Brown said.

Her parents reported her missing June 20, and the search since then has drawn national attention.

High-tech investigation

Nearly 24 hours before announcing the arrest, Brown had said there was no evidence of foul play in Lueck’s disappearance. Then, on Friday, Brown said breaks came when the Utah State Crime Lab confirmed tissue found at Ajayi’s home belonged to Lueck.

“This was outstanding detective work and cutting-edge technology,” the chief said.

Phone records showed Ajayi was the last person Lueck communicated with before she disappeared, Brown said. They also show Ajayi’s and Lueck’s phones were in Hatch Park within a minute of each other. The park is also the last place Lueck’s phone transmitted data, the chief said.

In a police interview with Ajayi, Brown said, the suspect asserted he texted Lueck about 6 p.m. June 16, but had no further contact with her. He said he didn’t know what Lueck looked like and said he hadn’t seen her photos or online profile, Brown said, but he had several photos of her, including an image from an online profile. Brown did not disclose which website the profile was on.

On Wednesday, investigators began an all-night search of Ajayi’s home in Fairpark. Neighbors reported seeing Ajayi using gasoline to burn something June 17 and 18 in his backyard, Brown said, and police found a “fresh dig area" in the same spot in the yard. They conducted a “forensic excavation” of that part of the yard and found several charred items matching the description of Lueck’s personal belongings, Brown said.

Police also found charred human tissue, Brown said. DNA testing showed a match for Lueck.

Police announced Friday evening on Twitter that they had located a mattress that had been taken from Ajayi’s home last week. Ajayi had used a social media app to give away the mattress and box spring last week.

There were several questions Brown declined to answer or said he didn’t know the answer to on Friday. The chief didn’t know if the June 16 texting was the first contact Lueck and Ajayi had.

Brown said he did not know the nature of any relationship Ajayi and Lueck had or why they met in Hatch Park — though address records show Ajayi had previously lived in an apartment about 0.2 miles from the park. Brown said he didn’t know where or when Lueck was killed. Other than saying “tissue” belonging to Lueck had been found, the chief declined to say what remains have been recovered.

Ajayi has no criminal history in Utah apart from some traffic citations. North Park police investigated a rape complaint against Ajayi in 2014, but didn’t pursue the case after the female victim said she didn’t want to press charges, according to a news release the North Park Police Department issued Friday.

Image builder

A friend of Ajayi who lived with him in the house for a few months in 2018 said the allegations are stunning for a man who tended carefully to his image as an educated, cultured professional. According to Ajayi’s LinkedIn profile, he has worked in information technology for Dell, Goldman Sachs, Microsoft and Comcast. He also modeled for fine art photographs.

“He's definitely a guy that likes to maintain an appearance,” said Sakari Moore, who said he first met Ajayi when they were in basic training together with the U.S. Army in Fort Jackson, S.C. In January 2018, Moore relocated to Utah and temporarily moved into downstairs rooms that Ajayi has advertised for rent on Airbnb.

“A.J. was a very bright guy, he knew his material. This is why it comes as a bit of a shock. To maintain his rapport of being well-read, with computers, with clients, and then to just flip a switch — I can’t really imagine it,” Moore said. “A.J. would be the kind of guy that’s, ‘Hey, let’s go to the Asian supermarket and buy a couple of crabs and go back to my house and eat.’”

As a roommate, Ajayi also “tends to have some anger issues,” Moore said. He would suddenly become “irate and disruptive” over small matters, Moore said, like disagreements over how furniture was arranged or the heat level used in cooking.

“He doesn't like to be told anything other than his way,” Moore said. “He snaps or loses his temper, [then] he comes back to his sweet self.”

Moore said he moved out because the tension was too persistent.

“I was nervous," he said, “because the polarity in his emotions [was] just switching very quickly.”

Moore said he never saw Ajayi act violently, toward him or anyone else. “I can’t really get a picture or a visual of him being this malignant person."

Moore said he wasn’t sure how Ajayi might behave in a dating relationship. Ajayi entertained a lot of different women while Moore lived there, Moore said, but he didn’t have any long-term romantic relationships.

In fact, Moore said he didn’t even know that Ajayi had been married. Ajayi and his ex-wife married in 2011 in Texas, and they separated in 2017; their divorce was finalized in January, according to court records.

It’s not clear that Ajayi accurately represented his military experience. His resume states he worked for the U.S. Army from 2014 to 2016, but Maj. David Gibbs of the Utah National Guard said he was a member for just six months in 2015 and 2016, and was discharged without completing his initial training requirements — either basic training or individual advanced training for specialized work.

“It doesn’t say good or bad performance, just [that he] couldn’t complete the initial training requirements to stay in he military ... for whatever reason,” Gibbs said.

Crime author

In 2018, Ajayi wrote a crime novel titled “Forge Identity.” According to the author’s biography, he was born and raised in Africa; his national origin is not identified, but the characters in the book live in Nigeria.

“[Ajayi] has survived a tyrannical dictatorship [and] escaped a real life crime,” the bio states. “He has been a salesman, an entrepreneur, and a writer.”

A plot summary on Goodreads.com states that “Forge Identity” is about a character named Ezekiel, who is 15 when he witnesses two murders and, in his trauma, is enticed to a life of crime.

“Ezekiel must decide if he will join the ranks of a criminal mastermind, or fight to escape the tyranny that has surrounded his young life. Or even beat them at their own game,” the summary states. “When trust is lost, can he even trust himself?”

Moore said he did not know when Ajayi moved to the United States. On his LinkedIn profile, Ajayi writes that he studied computer science at Utah State University from 2009 to 2017; Utah State University officials said he attended off and on between 2009 and 2016, with a break in attendance between 2011 and 2015. He did not obtain a degree, university officials said. A resume attached to his LinkedIn account states that he studied at London South Bank University in England from 2011 to 2015.

Court records show he received unemployment benefits at some point in 2017, and, in 2016, he was a defendant in eviction proceedings in Davis County. According to the LinkedIn profile, he has been employed in IT since 2017.

Airbnb reviews for Ajayi’s home date back to September 2018 and describe him as a “great responsive host” and “the kindest person.”

Moore said Ajayi did not rigorously screen guests, and there were some “who looked like they were homeless, who never cleaned up after themselves,” Moore said. He wondered whether any of them were involved in Lueck’s disappearance.

“I’m not sure what characters he’s allowed to live in his house who may have done this thing,” Moore said.

Remembering ‘Kenzie’

Lueck was from El Segundo, Calif., and long went by the nickname “Kenzie.” After graduating from El Segundo High School in 2014, she enrolled at the U.

She joined Alpha Chi Omega sorority. At the time of her death, Lueck was a senior majoring in kinesiology and prenursing, according to information provided by the university. While attending school, she also held jobs, most recently at a medical testing laboratory.

By Friday evening, the crime-scene tape had been removed from Ajayi’s house. Mourners left a line of sunflowers at the edge of the driveway, along with bouquets of flowers and two blue star-shaped Mylar balloons.

Friends of Lueck posted a fundraising page for her funeral expenses.

“We are all mourning Mackenzie’s death,” wrote her friend Kennedy Stoner. “We only feel it’s right that we start a gofundme page in honor of her, and any expenses that her family endures. We have come this far with Kenzie and won’t stop advocating for her. Our hearts are hurting and we are all experiencing anger, frustration, sadness, and loss.”

Stoner was one of Lueck’s sisters in the Alpha Chi Omegas sorority. The chapter remembered Lueck on social media Friday.

“We hope that our Alpha Chi Omega sisters who knew Mackenzie best can find peace and comfort as they reflect on the lasting impact she made not he lives of her family members, friends and sisters.”

Gov. Gary Herbert, saying he was “horrified and sickened” by the news, expressed his condolences to the Lueck family Friday.

As did U. President Ruth Watkins, who issued a statement.

“The death of MacKenzie Lueck is devastating news,” Watkins said. “On behalf of the university, I express our heartfelt sympathy to the family, friends and classmates of MacKenzie during this very difficult time.”

Salt Lake City Mayor Jackie Biskupski issued a statement complimenting Brown and his detectives and staff and offering sympathies to the Luecks.

“As a mother and a mayor, my heart breaks for the Lueck family," the statement reads. “Today, all of Salt Lake City mourns for them and stands ready to offer our support.”

Tribune reporter Sean P. Means contributed to this report.