Man arrested for murder, kidnapping of missing Utah student Mackenzie Lueck: Police Mackenzie Lueck, 23, was last seen in the early hours of June 17.

A Utah man was taken into custody Friday for allegedly killing missing University of Utah student Mackenzie Lueck, according to the Salt Lake City police.

Ayoola Ajayi, 31, is charged with aggravated murder, aggravated kidnapping, obstruction of justice and desecration of a body, Salt Lake City Police Chief Mike Brown said at a news conference on Friday.

Charred tissue has been recovered that contains DNA consistent with samples found on Lueck's belongings, Brown said.

Giving Lueck's father the news was "one of the most difficult phone calls I've ever made," Brown 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 Lueck met an individual at the park and did not appear to be in distress, police said.

The college senior was never seen again.

All communications from Lueck's cell phone stopped on at 3 a.m. that morning, Brown said.

Phone records show that Lueck and Ajayi were both at Hatch Park within less than one minute of each other, Brown said.

Lueck's last communication was with Ajayi, Brown said.

Ajayi admitted to police that he and Lueck texted about 6 a.m. on June 16, but said that they did not text after that time, said Brown. He told police "he did not know what Mackenzie looked like and denied having seen a photo or online profile of Mackenzie, despite having several photos of her and a profile photo," Brown said.

His home was searched on Wednesday night when he was considered a person of interest, police said.

During that search, Ajayi's neighbors told police they saw him using gasoline to burn something in his backyard on June 17 and 18, police said.

Police found a "fresh dig area" there, Brown said.

"A forensic excavation of the burned area was conducted, which resulted in the finding of several charred items consistent with personal items of Mackenzie Lueck," he said.

Lueck, a kinesiology major, was planning to graduate next year, according to the university.

"The death of Mackenzie Lueck is devastating news," university President Ruth Watkins said in a statement on Friday. "On behalf of the university, I express our heartfelt sympathy to the family, friends and classmates of Mackenzie during this very difficult time."

As her family and friends mourn, Lueck's connection to the suspect and details about the alleged crime remain unclear.

Investigators said Thursday they were looking to track down a mattress and box spring discarded from his house, police said.

Ajayi spent six months in the Utah Army National Guard, a Utah National Guard spokesperson told ABC News. He was discharged in June 2015, the spokesperson said.

Ajayi "did not attend Basic Training or Advanced Individual Training," said the spokesperson. "As a result, he did not receive any certificates or awards from the Army National Guard. He was therefore ineligible to deploy or conduct any tours of duty with the Utah Army National Guard."

ABC News' Clayton Sandell, Becky Perlow, Elizabeth Mclaughlin and Luis Martinez contributed to this report.