Mary F. Petruchius was born and raised in DeKalb, Illinois. She received her Bachelor of Science degree in Anthropology from Loyola University of Chicago. For two years, Ms. Petruchius taught Anthropology at St. Scholastica Academy in Chicago. During this time, she organized and presented the first all-high school rape prevention seminar in the City of Chicago in the early 1980's.

Ms. Petruchius received her Juris Doctorate degree from the John Marshall Law School, Chicago. She is admitted to practice law in the State of Illinois, the U.S. District Court for the Northern District of Illinois, the U.S. Supreme Court, and is a certified mediator. Ms. Petruchius completed mediation training with the Conflict Resolution and Divorce Mediation Institute and is a past member of the Mediation Council of Illinois and the Association for Conflict Resolution, an international mediation organization.

Mary Petruchius spent the first eight years of her legal career as an assistant public defender in Kane and De Kalb Counties. In 1995, she wrote and edited the Mental Health Law Handbook for attorney use in involuntary commitment and forcible medication hearings in Kane County.

In June of 2000, Ms. Petruchius partnered with Richard Schmack to form the general practice law firm of Schmack & Petruchius in Sycamore, Illinois. The firm concentrates in: Bankruptcy; Criminal Defense; DUI & Traffic Defense; Family, Juvenile, & Mental Health Law; Real Estate and Zoning; Wills & Estates; Guardianships & Adoptions; and Mediation.

Ms. Petruchius is a member of the DeKalb County and Kane County (KCBA), Illinois State (ISBA), and American Bar (ABA) Associations; KCBA's 150-Year Anniversary Planning Committee; ISBA's Standing Committee on Women and the Law and its Continuing Legal Education (CLE) and Outreach Subcommittees; ISBA's Standing Committee on Law Related Education; ABA's Commission on Women in the Profession, Law Practice Management and Women Rainmakers Section; Women's Criminal Defense Bar Association; National Association of Criminal Defense Lawyers; “Teach Tolerance” of the Southern Poverty Law Center; and The Supreme Court Society.

The mission of the Standing Committee on Women and the Law is to study and focus on areas of the law uniquely concerning women. The committee assesses, designs and implements programs designed to satisfy women's unmet legal needs. It studies and recommends legislation affecting women, provides a forum for action relating to women's issues, and explores ways to encourage women in their involvement in the legal community at all levels.

As a member of the Women and the Law's CLE Subcommittee, Mary Petruchius has participated in drafting, organizing, moderating and lecturing for two continuing legal education programs. "The Secret World of Human Trafficking" was held in January 2007 and "Girls' Justice: Delivered or Denied?" was presented in on October 4, 2007. She has authored and co-authored numerous articles for that Committee's newsletter.

In August 2007, the 2007-2008 ISBA President, Joseph Bisceglia, personally appointed Ms. Petruchius to the ISBA Standing Committee on Law Related Education for the Public (LRE). The purpose of the LRE is to develop, implement, and administer law-related education programs to enhance the understanding of the legal system and the role of lawyers in our society, including programs to educate the public and students of all ages about the important role of lawyers and judges, the importance of an independent judiciary for the proper administration of justice, and which foster an interest in students to respect our justice system and consider pursuing careers in the law.

Mary Petruchius is a Gold Fellow of the Illinois Bar Foundation, which is the charitable arm of the ISBA. She was recently appointed a position on the ISBA Assembly representing the 16th Judicial Circuit, the Bar Association's the rulemaking body.

Within her community, Ms. Petruchius is a member of the De Kalb County Juvenile Justice Council and its Truancy Committee. She is a volunteer attorney with Prairie State Legal Services, providing pro bono representation to individuals in divorce and family law cases. Mary currently serves on the executive boards for Kishwaukee Women's Network, the De Kalb County Hospice and Shelters for Healthy Environments, Inc., and is a former member and past president of the De Kalb County Community Mental Health Board. She is also volunteer at Pay-It-Forward House, a Ronald McDonald-type home for the families of patients in Kindred Hospital, in Sycamore, Illinois.