Mrs. O'Halloran received her undergraduate bachelor's degree from the University of Florida and her law degree from Loyola University of New Orleans where she graduated magna cum laude. She was distinguished as a William L. Crowe Scholar for graduating in the top 6% of her law school class. Before beginning her career in criminal defense, she worked as a student practitioner in the Orleans Parish District Attorney's Office and then as a prosecutor in the 20th Judicial Circuit, where she prosecuted all levels of misdemeanor and felony crimes, specializing in white collar crime prosecution. She has handled cases before courts in every county in the 20th circuit.

She is admitted to practice in the Florida Bar and the Federal Middle District Court of Florida. She is a member of the Florida Association of Criminal Defense Lawyers, The Criminal Law Section of The Florida Bar and the American Inns of Court- Calusa Chapter. In her spare time she is an adjunct professor for Rasmussen College, teaching in their Criminal Justice Department.