The head and skeletal remains found behind a bargain store in Anne Arundel County on Monday is that of a young woman who was killed with blows to the upper body, according to police who said the death has been ruled a homicide.

Few other details, including the woman’s identity, are known. Authorities said they are embarking on a search using dental records and DNA to try and learn who she was. Police said the remains had been there for at least several months.

Police said the skeletal remains found Monday are of a white woman with brown hair, 18 to 20 years old, and about 5 feet 6 inches tall.

A spokesman for the Anne Arundel County Police Department, Justin Mulcahy, said the remains “do not appear to be matching up with any of our missing persons.”

The department lists six open missing persons cases in the county, one dating back to 1976. The most recent is Jessica Lynn Lee, a 20-year-old who was last seen May 8 at a Shoppers Food store in the 5700 block of Ritchie Highway in Brooklyn Park, in northern Anne Arundel near the Baltimore City line.

She is described as a white woman with blond hair standing 5 feet 8 inches tall and weighing about 127 pounds.

Mulcahy said police officers were back at the scene in the 8100 block of Ritchie Highway in Pasadena, on Thursday.

“Now we’re trying to look for additional witnesses or evidence,” he said. “Certainly it’s difficult when dealing with remains. We’re not ruling anything out yet.”

The spokesman said the death has been ruled homicide by blunt force trauma to the upper body.

A man walking near Ollie’s Bargain Outlet found the skull shortly before 3 p.m. on Monday. Police searched the area with cadaver dogs from the Chesapeake Search Dogs and the Mason Dixon Search and Rescue Dogs and found more remains in woods “a good distance away,” Mulcahy said.

Authorities would not describe how much of the skeleton, or if any other evidence, was found.

Maryland’s chief Medical Examiner, Dr. David R. Fowler, would not comment directly on the case but said his office uses anthropologists with PhDs to examine human remains. Approximate age, sex and height can be determined by measuring leg and femur and pelvis, which differ in men and women. For example, joints age and wear differently in the sexes.

Fowler also said that dental records, which police routinely collect from missing persons, can be checked in at least two national databases.

Police and other authorities said that discoveries of human remains are unusual. But it’s the second such find in two days in Maryland.

On Wednesday afternoon, the Frederick County Sheriff’s Department said a tree trimmer found skeletal remains 10 to 15 yards off the 4100 block of New Design Road in rural Western Maryland.

No other details of the Frederick County case were available.