Human remains found in Alabama on Monday are believed to be those of Aniah Haley Blanchard, the teenage stepdaughter of UFC fighter Walt Harris. Blanchard was last seen outside a convenience store on Oct. 23.

Aniah Haley Blanchard. Auburn Police Department

The remains were found at approximately 10:45 a.m. in a wooded area in Macon County, near Shorter, Alabama, authorities said.

The district attorney in Lee County, Brandon Hughes, told NBC News that his office had "good reason to believe they are that" of Blanchard.

Blanchard, 19, a student at Southern Union College, was last seen in Auburn, Alabama. Her damaged car was recovered two days after her disappearance about 60 miles away in Montgomery, Alabama.

Authorities had initially said they did not suspect Blanchard was the victim of foul play, but changed their position after the Alabama Department of Forensic Sciences examined evidence from her 2017 Honda CR-V.

On Friday, police arrested Antwain Fisher, 35, of Montgomery, on first-degree kidnapping charges in the disappearance of Blanchard.

Ibraheem Yazeed, 29, was arrested this month in western Florida on the same charge. Yazeed was caught on surveillance video in the same store where Blanchard was last seen. He was out on bond for prior kidnapping and attempted murder charges when he was taken into custody.