(NewsNation) — A criminologist believes the man suspected of murdering a Maryland teacher “knew what he was doing” and “didn’t want to get caught.”

The Prince George’s County Police Department’s Homicide Unit announced Friday that Harold Landon III, 33, of University Park, has been identified as the suspect and charged with the murder of Mariame Sylla, 59, of Greenbelt.

Sylla disappeared at around 8 p.m. July 29 after going for her daily walk at a park in Greenbelt, which is about 15 miles northeast of Washington, D.C. Her remains were found Aug. 1 on Old Alexander Ferry Road in Clinton.

Authorities say they identified Landon as the suspect through various investigative techniques. He has been in Department of Corrections custody since Aug. 1 on an unrelated assault charge.

“This individual is so disturbed, so depraved, yet the good news is we have somebody in custody,” criminologist Dr. Debbie Goodman told “NewsNation Now.” “Police representatives generally don’t want to say too much at the beginning, when there’s such a high profile case.” Since the victim was “a beloved individual, a second grade teacher, they want to make sure that they’re very dutiful and diligent in the entirety, in totality, of the fact finding process.”

Landon now faces first-degree murder charges related to the death of Sylla.

“When we talk about a first-degree murder, four elements are present, according to the district attorney,” Dr. Goodman said. “And that would be: it was planned, it was premeditated, it was willful and it was with malice.”

An autopsy is being conducted to determine Sylla’s exact cause of death, and investigators are still working to reveal where and when she was killed.

“The fact that he (Landon) participated in the dismemberment, in the decapitation, suggests to me as a criminologist that he didn’t want to get caught,” Dr. Goodman said. “And if and when this case goes to trial, that’s going to be a very important point for the prosecution to demonstrate this individual’s mindset.”

The motive for the killing is still under investigation, but Prince George County police said there is no indication Sylla and Landon knew each other.

“Ms. Sylla was a beloved teacher and member of the Greenbelt community. Her murder is tragic. We hope the arrest of Landon provides some comfort to her family and all who knew and loved her,” Prince George County Police Chief Malik Aziz said.

Anyone with information relevant to the investigation is urged to call detectives at 301-516-2512 or Crime Solvers at 866-411-8477.