I am your St. Joseph County Prosecutor.
The success of our legal system requires those in positions of public trust to serve with integrity. Truth and justice cannot be recognized without integrity.

Chairman, SJC Republican Party

Whoever is careless with the truth in small matters
cannot be trusted with important matters.
– Albert Einstein

Working for those who call St. Joseph County their home.


I am the father of 3 children (and a beautiful German Shepherd dog and 2 cats), living in Lockport Township.

My great, great grandfather moved to Nottawa in 1866 after fighting in the American Civil War. My family has been serving our county ever since.

Public service runs in my blood. I was elected to serve as your st. Joseph county Prosecutor in 2020. My father, Robert T. Marvin served as a St. Joseph County Commissioner for 23 years and my grandfather, John W. Marvin, was our elected county clerk for 42 years. My grandmother, Jeanette Barnes, served as a Kalamazoo County Commissioner in the 1970’s. I was raised to be honest and hard-working and I’ve learned to be fair and efficient, applying these principles in my job every day.

The prosecutor’s job – to seek justice by helping people in need, defending victims of crime and holding wrongdoers responsible for violating our laws – requires integrity. A prosecutor must know that doing the right thing is more important than personal comfort, convenience and political pressure or social connections.

I have the great privilege of going to work every single day to find justice and to apply it equally and respectfully to all. I promote principles of individual responsibility and self-government.

The integrity of our legal system requires those in positions of public trust to serve and lead with integrity.

This is what I’ll continue to do as long as St. Joseph County will have me.


David Marvin earned his law degree from Michigan State University in 2001, spending more than a decade as a corporate attorney before entering private law practice.

  • Corporate Attorney – (6 years)
  • Director of Operations – (6 years)
  • Private Law Practice – (7 years)
  • St. Joseph Co. Prosecutor – (4 years)

David holds undergraduate degrees in Political Science and Philosophy from Principia College. He attended school in Beijing during his undergraduate studies and studied a semester at the University of Hong Kong Law School.


David spent 6 years in corporate management as Director of Operations of a land development company with a national footprint. This experience taught him to be practical and efficient since spending and human resource allocation directly impacted profitability.

The prosecutor’s office needed a leader when he began as Prosecutor in 2021. David made an immediate impact during a time when the office was severely compromised due to mismanagement and under distress with a heavy caseload backlog in the midst of the COVID pandemic.

David has begun the long and difficult process of uniting the law enforcement community, various government agencies and the courts for the common cause of serving the citizens of St. Joseph County.


We are all our best when individuals take responsibility and govern at the most basic levels: family, community and county. Self-government works only when citizens are informed and understand local government is where liberty begins – and too often ends.

St. Joseph County has been let down and embarrassed by several unfit to lead over the recent years and months.

We cannot fix Lansing or Washington – and we are never going to lead the world – if we don’t even have a handle on what is happening in Centreville.

The best leaders are already living and working right here in 521 sq. miles of St. Joseph County. Let’s find them. We need their help.


Endorsed by United Auto Workers

“Truth is the foundation upon which justice stands. In the pursuit of a fair society, honesty fuels the fire of accountability, illuminating the path towards a better world.”