Officers responded to the 19th Street station in regards to a dispatched call from an anonymous patron stating a male was being threatened by a female holding and waving a knife. Responding officers located the victim, and suspect on platform 1/3. The parties were engaged in an argument and the suspect was holding a 3.5 inch knife in her hand in the open position with the blade exposed. Officers took the suspect into custody at gunpoint and recovered the knife. Subsequently The suspect was issued a citation for 417(a)(1)P.C., given a prohibition order and taken to John George for psychiatric treatment. An officer took the report and a sergeant responded to conduct a use of force investigation.