Keiko Nishimura is a case agent in the Center for Immigration Services in New York City and presides over the cases of immigrant families whose children were being strangled to death by a bigoted serial killer. When all the children were revealed to be "anchor babies", American-born citizens of immigrant families who were keeping their parents with their green cards statuses, the family of one of the children gave detectives Keiko's business card.
She confirmed all families were affiliated with the agency and was horrified an employee even associated with the agency was behind the murders from having access to the families' information. Thankfully, partly with her assistance, the killer was revealed to be Joseph Thagard, an employee at a company responsible for shredding the papers with the agency's records when thy were finished with having them on file. Thagard stole the information and used it to make a hit list of the families. This led to Thagard being apprehended in the process of attacking another family and killing the father in an attempt to murder the couple's son. (SVU: "Anchor")