Eight patients and one staff member have tested positive for covid-19 at Maryland’s maximum-security psychiatric hospital, the Clifton T. Perkins Medical Center in Howard County, health officials said Monday.

The forensic facility, home to about 280 patients, houses men and women who suffer from mental illness and are accused or convicted of crimes. The hospital is now requiring all patients and staff to wear protective masks, said Charles Gischlar, a spokesman for the Maryland Department of Health. That department, along with health officials from Howard County, continued their investigation on Monday.

“Testing for health-care workers and patients of the facility is ongoing,” Gischlar said. Thus far, 13 patients had been tested, with eight positive results, two negative results and three pending, said Lisa de Hernandez, spokeswoman for the Howard County Health Department. Other precautions at Perkins, according to Gischlar, include taking patients’ temperatures twice daily, screening staff upon entry, limiting movement within the hospital and ending visitations.

Perkins performs a host of duties for its patients and Maryland’s criminal justice system. Doctors there evaluate whether patients understand their surroundings enough to be tried in court. Other, longer-term patients who have committed crimes, some violent, have been committed to Perkins.

Among the high-profile defendants sent there in recent years include two Montgomery County women: Catherine Hoggle, accused of killing her two young children who went missing in 2014and who has tried numerous times to escape from the institution, and Zakieya Avery, who admitted to killing two of her children because she thought it would release demons that had invaded their bodies.