Cold Case Investigations
Unsolved Doesn't Mean Forgotten.
When law enforcement has moved on, families are left without answers. Peak Investigations takes a fresh look at unsolved homicides, missing persons, and stalled cases — applying 30+ years of investigative experience and modern OSINT tools to find what was missed.
A Second Set of Eyes — With Nothing to Lose
Glen Dunsbergen spent decades in law enforcement and understands both the strengths and limitations of official investigations. Cold cases go cold for many reasons — limited resources, missed leads, outdated technology, or investigative tunnel vision. As a licensed private investigator, Glen operates without institutional constraints, allowing him to pursue angles that official investigations may have overlooked or deprioritized.
30+
Years Experience
AZ
Licensed PI
100%
Confidential
What We Do
Cold case investigations are complex and deeply personal. Glen brings a structured, evidence-based approach to every case.
Case File Review & Analysis
A thorough review of all existing case materials — police reports, witness statements, evidence logs, and court records — to identify gaps, inconsistencies, and unexplored leads.
Witness Re-Interviews
Locating and re-interviewing original witnesses, as well as identifying new witnesses who may not have been contacted during the original investigation.
New Lead Development
Using modern investigative techniques and OSINT tools to develop new leads from information that wasn't available — or wasn't pursued — at the time of the original investigation.
Social Media & OSINT Investigation
Deep-dive open-source intelligence research across social media, public records, and online databases to surface connections and information unavailable to earlier investigators.
Suspect & Person of Interest Research
Background investigation of known suspects, persons of interest, and newly identified individuals — including criminal history, location history, and behavioral patterns.
Evidence Documentation & Reporting
All findings are documented in a clear, organized report suitable for submission to law enforcement, attorneys, or use in civil proceedings.
Who We Work With
Families of Victims
Families who have waited years — or decades — for answers and are no longer willing to accept that the case is closed. Glen works directly with families to pursue the truth.
Defense Attorneys
Legal teams seeking independent investigation of cold cases where a client may have been wrongfully convicted or where new evidence may exonerate the accused.
Journalists & Documentarians
Investigative journalists and documentary filmmakers who need a licensed PI to conduct on-the-record investigation and provide verified findings.
The Peak Investigations Approach
Cold cases require patience, objectivity, and a willingness to challenge prior assumptions. Glen approaches every cold case without preconceptions — following the evidence wherever it leads, not where it's convenient. He works closely with families throughout the process, providing regular updates and treating every case with the gravity and respect it deserves.
Evidence-First
Every conclusion is grounded in documented, verifiable evidence — not speculation or assumption.
Family-Centered
Families are kept informed throughout the investigation. Glen understands this is personal, not just professional.
Legally Sound
All investigative methods comply with Arizona law, and findings are documented in a format suitable for legal proceedings.
How It Works
01
Confidential Consultation
Speak with Glen directly about the case — what happened, what was investigated, and what you're hoping to find. No obligation, complete privacy.
02
Case Assessment
Glen reviews available case materials and provides an honest assessment of what a private investigation can realistically accomplish.
03
Active Investigation
Glen pursues new leads, re-interviews witnesses, and applies modern investigative tools to develop a clearer picture of what happened.
04
Report & Next Steps
Findings are compiled into a detailed report. Glen advises on next steps — whether that's submitting findings to law enforcement, working with an attorney, or continuing the investigation.
It's Not Too Late to Find Answers
If you have an unsolved case and need someone to take a fresh look, contact Glen today. Every case deserves a second chance at the truth.