Federal police officers arrested a Silver Spring, Maryland, woman suspected of attempting to steal sensitive medical specimens and equipment from the clinical center of the National Institutes of Health in Bethesda.

The woman, Chinyere Okunji, is unemployed and suspected of having mental health concerns, according to testimony in court Wednesday. She wore a lab coat with a University of Rochester logo, but does not work for the school or NIH, according to a detention order issued by a federal judge.

The agency said Okunji entered the grounds through the NIH visitor screening process and was issued a visitor's pass. But the agency said it is unaware of why she was on the campus.

The woman was acting suspiciously and "trying to open hospital freezers, which are kept locked and may be accessed only by authorized hospital employees," according to a police affidavit obtained by the News4 I-Team.

The incident occurred Aug. 21 in Building 10 at the NIH clinical center, which is home to about 1,600 clinical studies, including into rare diseases.

Police arrested Okunji, who was ordered detained pending trial at a court hearing Wednesday at the U.S. District Court in Greenbelt. She is charged with stealing U.S. property.

According to the NIH police affidavit, "Unknown to any of the hospital personnel, she entered restricted areas of the hospital by following authorized medical personnel into those areas. She was carrying a number of white plastic patient bags containing items belonging to NIH. When confronted by hospital personnel, she said at different times that she was a doctor, was going to see a patient, was with the phlebotomy lab, and was with another clinic."

According to the affidavit, Okunji was found holding bags with specimens of "human peptides" that required refrigeration and were stolen from a medical researcher. The affidavit said she was also found carrying a medical thermometer and hundreds of slides belonging to the hospital.

"The NIH is reminding employees that even if someone is wearing a lab coat or hospital staff attire, that person should still have a valid NIH ID visible," an NIH spokeswoman said. "Employees should not hesitate to question individuals in non-public areas that aren't displaying proper identification and are not known to the employees that work in that area."

Okunji, 29, did not speak during the Wednesday afternoon hearing. She is scheduled to return to court in October. The judge ordered a psychological exam of Okunji.

"We don't know what she did when she had access back there (at NIH)," a federal prosecutor said during Wednesday's court proceedings.

The prosecutor said the feds have not yet completed an estimate of dollar amount or worth of the items stolen.

In his detention order, a federal judge called the items stolen "a weird assortment of rare specimens." The items were taken from the surgery theater at the facility and from freezer knit areas, the judge said.

Okunji's defense attorney declined to comment.