
John G. De Koster
John has engaged in the general practice of law for over 35 years. He spends a majority of his time addressing estate planning and probate matters, real estate law, and tax planning and preparation. Before joining De Koster & De Koster, he practiced for four years in the Office of the Solicitor of the United States Department of the Interior in Washington, D.C.
John obtained his Doctor of Jurisprudence from the University of Colorado School of Law graduating in the top 10% of his class and awarded Order of the Coif. While in law school he worked in the legal aid clinic representing criminal defendants and clerked for the Denver firm of Lohf & Barnhill.
Before attending the University of Colorado School of Law, John graduated with distinction and honors from Iowa State University with a major in political science and a minor in history. While at Iowa State University he sang in the University Chorus and participated in residence hall student government.
John is an active member of the American Reformed Church in Hull, Iowa, where he has served as both an elder and deacon and has taught adult Sunday school classes. He is the president of the Hull Community Foundation, a board member of the Hull Industrial Development Corporation and serves as the Secretary/Treasurer of the Hope Cemetery Association. In his free time he golfs, follows the Cleveland Indians and Iowa State Cyclones and travels, when time permits.
Bar Admissions:
– Iowa State Courts
– Supreme Court of the United States
Professional Associations and Memberships:
– Sioux County Bar Association
– Iowa State Bar Association
– American Bar Association

Philip J. De Koster
Philip has a diverse practice, covering almost all of the firm’s practice areas. He spends most of his time working on estate planning and probate matters, real estate law, corporate law, appellate advocacy, and assisted reproductive technology law. Before joining De Koster & De Koster, he practiced for three years with LaMarca Law Group, P.C., in Des Moines, Iowa.
Philip obtained his Doctor of Jurisprudence from Drake University where he graduated summa cum laude, Order of the Coif, and was a Dwight D. Opperman Scholar. In addition to his academic achievements, Philip competed on the ABA and National Moot Court teams. During law school, he was recognized for his volunteer work, his excellence in client representation and advocacy, and for his service to the Moot Court Programs. After graduation he was awarded the Iowa State Bar Association Graduating Senior Award.
Before attending Drake Law School, Philip graduated with distinction and honors from Iowa State University with a major in Sociology and minors in Criminal Justice, Political Science, and Music. At Iowa State, he served on many levels of residence hall student government and was a teaching assistant in the Sociology and Political Science departments.
In his free time, Philip enjoys both indoor and outdoor gardening and is a licensed private pilot. He is an active member of American Reformed Church in Orange City, Iowa, where he plays music as a co-music leader with his wife. Philip also teaches Business Law at Northwestern College in Orange City. He has also created an award in honor of Dr. K.M. Waggoner to recognize Drake law students who mentor their peers.
Bar Admissions:
– Iowa State and Federal Courts
– Supreme Court of the United States
Professional Associations and Memberships:
– Sioux County Bar Association
– Iowa State Bar Association
– American Bar Association

Jennifer A. Randolph
Jennifer joined De Koster & De Koster in 2019 after graduating from law school. Her primary interests are criminal law and family law. Her practice also includes the remainder of the firm’s practice areas, including real estate, estate planning, and assisted reproductive technology law.
Jennifer obtained her Doctor of Jurisprudence from Drake Law School where she graduated with honors. She received certificates in Criminal Prosecution and Defense and Mediation. While in law school, Jennifer worked in Drake Law School’s Criminal legal clinic and interned at both the Polk County Prosecutor’s Office and the Polk County Public Defender’s Office.
Before law school, Jennifer graduated with honors from the University of South Dakota with a major in Criminal Justice and received a minor in Psychology from South Dakota State University. Jennifer also obtained an Associate of Arts degree with honors from Northwest Iowa Community College. While obtaining her bachelors and associates degrees, Jennifer worked full time as a Certified Nursing Aide in local hospitals and nursing homes.
In her free time, Jennifer follows the Vegas Golden Knights and the Iowa Hawkeyes. A Northwest Iowa native and a new mother, Jennifer enjoys being back in the area and raising her daughter within the small-town atmosphere.
Bar Admissions:
– Iowa State Courts
Professional Associations and Memberships:
– Iowa State Bar Association
– Young Lawyers Division of the Iowa State Bar Association
– Sioux County Bar Association