Investigators said they found the body of Allisha Watts in Montgomery County, North Carolina, on Thursday.
She had not been seen since July 16.
The Montgomery County Sheriff's Office said Watts' boyfriend, James Dunmore, has been arrested at his Charlotte home and charged with murder.
"This is not the otucome we were hoping for," Montgomery County Sheriff Pete Herron said at a brief media conference Thursday afternoon.
Watts had last been seen more than a month ago at Dunmore's home, according to police.
The Charlotte-Mecklenburg Police Department had been investigating Watts' disappearance.
"This case is no longer considered a missing person investigation," CMPD said Thursday.
Montgomery County, where Watts' body was found, is a largely rural area east of Charlotte. The Uwharrie National Forest makes up much of the county.
"Our hearts go out to the family and friends of Ms. Watts," Moore County Sheriff Ronnie Fields said at the press conference.
Fields said the investigation remains active.