Murder Sheet – "A Talk with ISP Forensic Genealogist Bradley Marchant Part Two: The First Person That Knows"

Date: March 31, 2026
Guests: Áine Cain (Host), Kevin Greenlee (Host), Bradley Marchant (Indiana State Police Forensic Genealogist)
Theme: The complex and crucial role of forensic genetic genealogy (FIG) in solving cold cases, exonerating the innocent, and balancing ethics and privacy in modern investigations.

Episode Overview

In this in-depth conversation, journalist Áine Cain and attorney Kevin Greenlee continue their interview with Bradley Marchant, a forensic genealogist with the Indiana State Police (ISP). Marchant offers a behind-the-scenes look at how DNA and family trees are used to unearth the truth in murder cases, exonerate wrongfully convicted individuals, and restore identities to the unidentified dead. He also explores the emotional and ethical considerations involved in working with highly personal genetic data.

Key Discussion Points & Insights

How Cases Are Investigated with FIG

• Building Family Trees from DNA Matches

  • Marchant explains how law enforcement uses DNA matches from third or distant cousins to construct family trees that lead to potential suspects, victims, or unidentified remains (Jane/John Does).
  • “Let’s say Kevin turns out to be the brother to a serial killer...He hadn’t taken a DNA test, but let’s say his third cousins had taken it and led us to Kevin...” (04:00)
  • In most cases, close relatives are not directly contacted unless absolutely necessary to confirm a lead or obtain a DNA sample for comparison.

• Garbage Pulls & Direct DNA Collection

  • Though the media suggests police routinely retrieve DNA from discarded items (“garbage pulls”), Marchant clarifies this is not standard practice and happens only in select situations.
  • Investigation relies on a careful combination of genetic data and corroborating evidence—DNA alone is never the only reason for an arrest or indictment. (05:56)

FIG for Exonerations

• FIG is also wielded to free the wrongfully convicted: “As fig gets bigger and bigger, I think we’re going to see it be used more and more for exonerations.” (06:11)

Adoptees, Family Secrets, and Unexpected Discoveries

• Adoptees are a significant group in DNA databases, often seeking their own biological roots, which can both help and complicate casework.
• Challenges: Adoption and unknown parentage can create “brick walls” in building accurate trees, especially if individuals are unaware of their own adoption or their real parentage.
  • Memorable anecdote: Marchant describes working on a case where a maternal adoption or a “baby switched at birth” was evident, but he purposely avoided contacting the involved individual to prevent trauma. (11:10–12:27)
• Approach to Privacy: The ISP team actively chooses not to contact individuals where revealing unexpected familial truths risks disruption or harm.
  • “...decided to shelve that person. I’m not going to pursue that family tree any further because contacting her might be traumatic and disrupt her life.” (12:07)

Database Limitations, Trust, and Privacy

• The potential for solving cases is proportional to the size of the DNA database, which is smaller than major consumer sites (e.g., Ancestry or 23andMe).
• Building Trust: Marchant emphasizes ISPs commitment to privacy—case DNA profiles are deleted once solved, and strict ethical standards exceed federal requirements.
  • “Once the case is solved, we actually delete the information.” (45:52)

The Thrill and Burden of Being “The First Person Who Knows” (19:16–20:21)

• Memorable moment: Marchant shares the emotional experience of being the first to crack a major case—sometimes after hours, with no one to tell due to confidentiality.
  • “I want to tell somebody within seconds, but of course, I can’t...” (19:19)
  • He likens case announcements to sharing a child’s art project with a parent: “...that’s my kid that did that.” (20:17)
  • Genealogists rarely receive public recognition, despite being pivotal in resolving high-profile or long-neglected cases.

Assigning Cases – Difficulty, Language Skills, and “Brick Walls” (24:02–27:18)

• Marchant doesn’t choose his cases; the most difficult cases often go to him due to his extensive experience and ability to research in 7–8 languages.
• Cases are assigned by the needs of the lab and consulting with police investigators.
• Some cases linger for years due to poor-quality DNA and need multiple rounds of testing.

“Target Testing” and Minimizing Intrusion (27:18–35:56)

• “Target testing” helps pinpoint a specific lineage within a tree if the relationship isn’t clear—using voluntary DNA tests from more closely related family members.
• FIG has reduced the impact on the public compared to earlier methods, which required hundreds of unrelated people to be tested:
  • Golden State Killer case required “about 300 people” (29:50); with FIG, that number has dropped to a handful.
• Success is defined by how little disruption is caused outside the person of interest:
  • “As much as possible, we don't want to target test. We want to be least disruptive as possible.” (35:25)

Engaged Public and “Crime Scene Enthusiasts” (35:56–37:13)

• Some contacted individuals relish the chance to help, seeing themselves as part of a “CSI episode”—sometimes they directly supply crucial info.
  • “She said, ‘I want to do what you do. I want to solve these cases.’ And I said, well, actually, you are a part of that right now.” (36:20)
• Hosts emphasize: any listener's DNA could play a key role in solving a case.

Emotional Impact and Legacy (38:03–45:11)

• Marchant views genealogy as his “superpower” and has helped numerous people find relatives, leading to profound emotional reactions.
  • “One person burst into tears because I found out where her family came from in Norway...she’d been looking for 50 years.” (38:26)
• The emotional impact extends to families of the missing and murdered: offering closure and healing for those who thought they’d never get answers.
  • “Just to know that I’m able to provide, you know, some closure...I know it’s healing.” (40:05)
• The work is unique—solving crimes by day, gardening at night (“my garden during the day...at night, I’m solving crimes”). (44:43)

Strict Ethical Practices

• Privacy first: After a case is solved, all DNA and identifying information used in the investigation is deleted from law enforcement databases.
  • “Once the case is solved, we actually delete the information...” (45:52)
• Standards at Indiana State Police exceed federal guidelines. ISPs do not upload to consumer sites like MyHeritage; privacy protocols are set before cases are opened.
• The potential for legacy: DNA uploaded by deceased individuals continues to help solve cases—sometimes years after their death. (50:07–50:59)
  • “If she is somewhere that she knows what's going on, I kind of think that she'd be thrilled knowing she's solving a genealogy mystery and she's not even on this earth anymore.” (50:48)

Notable Quotes & Memorable Moments

“I get to be the first person, you know, like, I get to see it and I see, oh, the family trees are all combining and it's all looking like it's this one person. And I'm the first one.”
—Bradley Marchant, (19:16)

“Our goal is to keep it as anonymous as possible...The more that we build trust, the faster things are going to go.”
—Bradley Marchant, (17:18/49:50)

“Every case is completely different. But you know, it's exciting and I love being that kind of first person that knows.”
—Bradley Marchant, (21:40)

“...decided to shelve that person. I'm not going to pursue that family tree any further because contacting her might be traumatic and disrupt her life...”
—Bradley Marchant, (12:07)

“Sometimes I say, this is really good genealogy that I'm doing...it's like I sometimes I say, this is really good genealogy and no one's ever going to see it but me.”
—Bradley Marchant, (46:25)

“Your DNA could solve it...And maybe you'll never know that your DNA was the part that solved that crime.”
—Bradley Marchant, (37:17)

Timestamps for Important Segments

• [01:44] – Genealogy tree-building and case examples
• [04:00] – Pathways to identify people via distant DNA matches
• [05:56] – Use of DNA for both identification and exoneration
• [11:10] – Adoption and family secrets in investigation
• [12:07] – Team's ethical approach to privacy and minimizing trauma
• [17:18] – Scope of ISP work and privacy protections
• [19:16] – The thrill and frustration of being the “first to know”
• [23:46] – How cases are assigned, need for diverse skills
• [27:18] – Target testing and reducing public intrusion
• [35:56] – Crime enthusiasts as accidental contributors to cases
• [37:17] – Power of unknowing public involvement
• [40:05] – Closure and healing for families
• [45:52] – Deleting DNA data post-case, privacy practices
• [50:07] – Legacy & the lasting influence of DNA in solving cases

Summary / Takeaway

This episode underscores the profound impact of forensic genetic genealogy—both in criminal justice and reuniting families—in a manner that is deeply personal, methodical, and ethically conscious. Bradley Marchant gives listeners rare insight into the painstaking, sensitive, and sometimes lonely work of unmasking decades-old truths. Listeners are encouraged to see themselves as part of a broader movement: every DNA kit taken and uploaded might help close a cold case or clear an innocent person. Through rigorous privacy protections and an abiding respect for the living and the dead, the Indiana State Police’s genealogy team is quietly changing countless lives, one case at a time.