A worker at Maryland's new juvenile detention center in Baltimore faces charges stemming from an alleged assault on a 15-year-old resident, court records show, underscoring growing concerns about the safety of children held at the pretrial facility.

Roslyn DeShields, 40, is to appear in Baltimore Circuit Court this month to answer charges of custodial child abuse and second-degree assault. A police affidavit alleges that she struck the boy "one time in the face with her hand" as he was being held against a window by another staff member, resulting in "a small welt and swelling under [the boy's] right eye."

The affidavit says the Aug. 27 incident was witnessed by Terry Curtis, a deputy facility manager at the Baltimore City Juvenile Justice Center.

Late last night, DeShields acknowledged that an incident was under investigation but denied knowing anything about charges pending against her. She also said she has been told that she will be fired next week.

LaWanda Edwards, a spokeswoman for the Maryland Juvenile Services Department, which operates the facility, said department policy generally requires that "any person . . . arrested or charged would be immediately removed from working with a child or children."

She added, "An investigation is done by us, and if we've found there is justification and we feel that they have abused a child, we can terminate them," regardless of the outcome of a police investigation or court case.In a report last month, independent monitors said conditions at the center pose "threats to the life, health and safety" of the residents. Also last month, Maryland Public Defender Nancy S. Forster asked a judge to close the facility or order immediate improvements there, citing "systemic" violence and allegations that workers have induced young residents to fight one another.

The center opened last Oct. 30 after more than a decade of planning and construction. It was intended to provide desperately needed space for boys, mostly 14 to 17, awaiting trial on offenses that typically included auto theft, simple assault and drug possession.

The Office of the Independent Juvenile Justice Monitor contended in its report last month that the situation there is so volatile that public defenders and "various ministerial and volunteer groups have not been visiting the facility for fear of their own safety."

Affidavits attached to Forster's petition contain additional allegations. One teenager said staff members "start fights by paying kids with cigarettes . . . to fight other kids." Another said he needed four stitches after being punched in the face by a staff member. A third said staff members "would bring in marijuana for kids to smoke."

Del. Robert A. Zirkin (D-Baltimore County) said: "This is prevalent all throughout the system. I guarantee it. Until we address the structural problem, it will continue."

Staff writer Matthew Mosk contributed to this report.