Moments before District of Columbia police found Jiamei Tian hiding in a bathroom stall at Washington National Cathedral, a family of tourists had spotted her in a back pew of the Children's Chapel guarding two bags and muttering softly in a foreign language.

Tian's unsettling behavior continued Tuesday, when the 58-year-old Chinese national made her first appearance in D.C. Superior Court to face charges in connection with a string of vandalism in which churches and tourist attractions across the city were spattered with green paint.

Tian refused to cooperate with the D.C. police department's Asian Liaison Unit, according to officials at her court appearance. She wouldn't say where she stayed in Washington. She told police that she had lived in Los Angeles, but prosecutors said they could find no evidence of that. She speaks little or English. Her visa to visit the United States expired three days ago.

As authorities investigate crimes that marred the Lincoln Memorial, a statue of the Smithsonian's first secretary and sanctuaries in two churches — one with a toxic mixture of paint, urine and feces — it may be as challenging to understand who Tian is as it will be to determine a motive for the vandalism. D.C. Police Chief Cathy Lanier said Tuesday the suspect may have "mental health issues."

D.C. Magistrate Judge Lori Parker ordered Tian to remain in jail until her next hearing Aug. 2; so far, she faces a single charge of defacing property for an attack on National Cathedral, which carries a maximum sentence of 10 years in prison and a fine up to $5,000.