|“||And in the end, justice was served, that's what matters.||”|
— Judge Frost in "Green Light"
Very little is known about Frost, other than she became a federal judge who presided over cases involving violations of federal law.
Frost presided over Reid's trial when he became the prime suspect in the murder of a Mexican-American woman named Nadie Ramos in Mexico. She first listens to Reid's attorney, Fiona Duncan, when she tells her about Reid's schizophrenic mother who has Alzheimer's disease and Reid being an FBI agent for over a decade. However, the prosecutor, A.U.S.A. Manny Martinez, counters her argument, saying that Reid violated federal protocol by sneaking across the border without notifying the FBI. Frost takes Martinez's side and denies Reid's bail.
Frost later has a meeting with Prentiss and Martinez at the courthouse. Prentiss informs Frost that new evidences indicates Lindsey Vaughn was responsible for Nadie's murder since her fingerprints were found at a new crime scene, but Martinez says that these are all theories. Then, Frost tells Prentiss that the evidence must be checked out thoroughly and it will take time, but Prentiss tells her that Reid doesn't have time. Later, once the evidence is reviewed, Frost has Reid released from prison. The following night, Prentiss thanks Frost over the phone for helping, but Frost tells her not to thank her as Prentiss risked everything as she brought the fingerprints in time. Then, Prentiss apologizes to Frost for her conduct in her chambers. Frost tells Prentiss that, given the circumstances, it was understandable and bids her a good night.