A body hidden under a mattress left in an industrial area near Alabama’s biggest city has been identified as that of a woman missing since February, authorities said.

Police said the remains found in Bessemer, a community just southwest of Birmingham, were those of 30-year-old Tiffany Osborne, news outlets reported.

Osborne was last seen Feb. 17 leaving her home to go to a neighborhood store. Midfield Police Det. Michael Jeffries said her boyfriend told investigators she left and never returned. She was reported missing two days later.

Bessemer police were called to an unfinished road at a site known for illegal trash dumping around 9:30 a.m. Wednesday. A utility worker cutting grass in the area spotted the remains, police Lt. Christian Clemons said.

The body had been concealed under an old mattress, according to Clemons.

Authorities said an autopsy on Thursday confirmed their suspicions that it was Osborne’s remains.

Osborne was a mother to three children, including a 3-month-old. Her death is being investigated as a homicide. Details surrounding her death or possible suspects weren’t immediately released.