A tech worker was charged Wednesday with murder and kidnapping in the death of a Utah college student whose body was found in a wooded area with her arms bound behind her. Prosecutors said Ayoola Ajayi, 31, was the last person Mackenzie Lueck communicated with on June 17 before she disappeared.

District Attorney Sim Gill said Lueck's cause of death was blunt force trauma to the head and her body was found with her arms bound behind her. Gill did not discuss a motive or possible connection between Lueck and Ajayi.

He became emotional as he described the Lueck family's reaction to the charges. "They asked me to express on their behalf the generosity of so many strangers and friends," he said.

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Lueck disappeared shortly after she returned from a trip to her California hometown for the funeral of her grandmother and took a Lyft from the airport to a park, where she met someone. Cellphone data put Ajayi in the park at the same time, police said.

Police said they discovered charred tissue that matched Lueck's DNA in the backyard of Ajayi's Salt Lake City home. Also in Ajayi's backyard, according to police, were charred personal belongings of Lueck's.

Neighbors told investigators Ajayi had been burning something on June 17 that smelled "horrible," court documents obtained by CBS affiliate KUTV reported. The documents said Ajayi's car had a strong odor of gasoline and a red gas can in the trunk, similar so a gas can he had purchased on June 25.

Ajayi was arrested June 28 as the search for Lueck continued. Her body was found buried in a canyon on July 3, about 85 miles away from the University of Utah, where she was a student.

Ajayi was charged with one count each of aggravated murder, aggravated kidnapping, obstruction of justice and desecration of a human body.

Ayoola Ajayi SALT LAKE COUNTY JAIL

Lueck has been remembered as a bubbly, nurturing person. She was a member of a sorority and a part-time senior at the university studying kinesiology and pre-nursing.

Ajayi is an information technology worker who had stints with high-profile companies and was briefly in the Army National Guard.

He has no formal criminal history but was investigated in a 2014 rape allegation and was arrested in a stolen iPad case at Utah State University in 2012. The arrest and the expiration of his student visa led to him being banned from the campus for about three years.

A native of Nigeria, Ajayi is now a U.S. citizen, records show.