Missing University of Utah sorority sister Mackenzie Lueck has been confirmed as dead — and authorities busted a former U.S. Army information technology specialist Friday for allegedly killing her and burning her body, officials said.

Ayoola Ajayi, 31, has been arrested on charges of aggravated murder, aggravated kidnapping, desecration of a body and obstruction of justice, police said at a Friday press conference.

“The arrested person’s neighbors informed detectives that they observed him burning something in his backyard with gasoline on the dates of June 18 and June 19,” Salt Lake City Police Chief Mike Brown said. “The search warrant resulted in the findings of a fresh dig area on his property which is the same area that the arrested individual was reported burning something.”

“A forensic excavation of the burn area was conducted, which resulted in the finding of several charred items that were consistent with personal items of Mackenzie Lueck,” he added.

“Other charred material was located which has now forensically been determined to be female human tissue. A DNA profile of that human tissue was obtained during forensic testing by the Utah state lab. That DNA profile was compared and is consistent with the DNA profile obtained through further forensic testing of personal items of Mackenzie Lueck.”

Lueck’s last text communications were with Ajayi, officials said.

Ajayi, as well as another man, were seen outside an apartment complex around 9:30 a.m., walking toward the SWAT team with their hands over their heads, local station KSL reported. It was unclear whether the other man was still in custody.

Meanwhile, local contractor Brian Wolf told FOX News that Ajayi reached out to him in April to request a secret, soundproof room in his basement.

“He slowly added on other requests, like building a secret door and adding hooks to the wall,” Wolf told the network, adding that the man had requested he come to the home and give him an estimate for the cost of the work.

The homeowner wanted the construction done as soon as possible, “before his girlfriend got back into town,” Wolf told FOX.

Wolf said he turned down the offer, claiming he was too busy — but he was really just “weirded out.”

Lueck, who is from El Segundo, California, vanished within hours of arriving at the Salt Lake City airport on June 17 from a trip home for her grandmother’s funeral.

The college senior called a Lyft from the airport to Hatch Park in North Salt Lake, where the ride-share driver saw her jump into another vehicle just before 3 a.m. with an unknown individual, authorities said.

Investigators had also been digging into Lueck’s dating apps after receiving tips that she was interested in older men and casually seeing several people.

A Linkedin page for Ajayi indicates that he has worked for Dell, Goldman Sachs, Microsoft, Comcast and the U.S. Army, where he was an information technology specialist from 2014 to 2016.

He was discharged from the Utah Army National Guard in June 2015 after six months of service, the National Guard’s public affairs officer told KSL.

Ajayi was also a member of the 214th Forward Support Company in Tooele, Utah, Gibb told the outlet. As he did not go through basic training and did not receive any certificates or awards, he was ineligible to deploy with the Army National Guard, Gibb added.

He was discharged because he did not meet “medical procurement standards,” Gibb said.

He also appears to have done some modeling work — and has a page on ModelManagement.com.

Eerily, he self-published a fictional book last August called “Forge Identity” that follows a young man named Ezekiel who witnesses an angry mob burning his neighbor — and then another loved one, alive. Ezekiel must decide whether to become embroiled in a life of crime, or make his escape.