Attorney Resource Portal

The Defense Investigator
Advantage.

IAI provides criminal defense attorneys in the Southern District of Texas, Harris County, and Fort Bend County with command-level investigative expertise — the kind that comes from four decades of running the investigations you are now challenging.

Refer a Case to IAI Execute Retainer Request Consultation
IAI At a Glance
►CJA Panel Vendor — Southern District of Texas
►Approved Vendor — Harris County Courts
►Approved Vendor — Fort Bend County Courts
►Two Certified EyeDetect® Examiners (Converus)
►PCSOT Certified Examiner on Staff
►Ph.D. in Public Safety Leadership — Police Leadership
►Active TCOLE Master Peace Officer License
►Minority Women-Owned Business
►Bilingual: English & Spanish
►TX Lic. A19944401
The Case for IAI

What Your Case File
Isn’t Telling You

Law enforcement investigations are built to secure convictions — not to find the truth. Every case file that crosses your desk was assembled by an agency with a predetermined conclusion. IAI was built to read those files the way the agency never wanted anyone to.

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Unchallenged Evidence
Law enforcement reports are rarely scrutinized for procedural compliance, chain of custody failures, or agency policy violations — unless defense counsel has an expert partner who knows exactly where to look. Dr. Walwyn spent four decades writing and enforcing those policies.
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Credibility Left Untested
Witnesses, informants, and cooperating defendants make claims that go unchallenged. Without independent credibility assessment, your client’s version of events may never be properly evaluated before you advise on a plea or commit to a defense theory.
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Missed Defenses
Procedural failures, constitutional violations, and investigative misconduct are embedded in case files — but finding them requires someone who has run these investigations from the command level. IAI reviews files the way the agency hoped no one would.

“Your clients deserve an investigative partner who speaks the language of the agencies they are challenging.”

— Dr. Celvin G. Walwyn, Ph.D. · Executive Director, IAI
Full-Spectrum Support

What IAI Brings
to Every Case

Most attorneys underutilize investigators. Here is the complete scope of what IAI delivers — from the moment you receive the case file to the day your client walks out of court.

Service 01
Case File Review & Agency Policy Analysis
We read the entire file — police reports, body cam logs, chain of custody records — looking for inconsistencies, policy violations, and constitutional issues. Every law enforcement agency has written SOPs. We compare what officers did against what their own policies required and document every deviation.
Service 02
Pre-Sentence Investigation (PSI) Review
Independent line-by-line analysis of the probation officer’s PSI report. We identify misclassified prior convictions, inflated criminal history scores, unsupported guideline calculations, and overlooked mitigating factors. We deliver a written analysis you can use directly in sentencing objections and oral argument.
Service 03
Witness Location & Interview
We locate and interview witnesses law enforcement may have missed, ignored, or discouraged — building the alternative narrative your client deserves. All statements are documented and preserved in court-ready format. Subject locate services available across Harris, Fort Bend, and surrounding counties.
Service 04
EyeDetect® Credibility Assessment
Two Converus-certified EyeDetect® Examiners on staff. We evaluate the credibility of your client, witnesses, and informants using scientifically validated ocular-motor technology — with up to 95% accuracy, no physical contact, and results in under 30 minutes. PCSOT-compliant testing also available.
Service 05
Mitigation Investigation
Comprehensive background investigations uncovering mental health history, trauma, family dynamics, and character witnesses. We build the full picture that courts need to sentence fairly — the human context that no probation report adequately captures.
Service 06
Expert Testimony & Consultation
Dr. Walwyn provides expert testimony on law enforcement procedure, use of force, agency policy compliance, and investigative conduct — with credentials no opposing expert can match. Available for affidavits, deposition preparation, and court testimony in federal and state proceedings.
Court-Approved

Tri-Level Court Authorization

IAI is approved at every level where your clients need investigative support. Court-appointed counsel can retain IAI directly with zero bureaucratic friction.

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U.S. District Court — SDTX
CJA Panel Vendor
Court-appointed by the Southern District of Texas. Federal CJA cases can retain IAI directly — covering Houston, Laredo, McAllen, Victoria, and Corpus Christi divisions.
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Harris County District Courts
Approved Vendor
Approved investigations vendor in Harris County. 12 years of insider knowledge of Harris County Corrections — booking, release, and institutional processes — is a direct asset to your defense.
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Fort Bend County Courts
Approved Vendor
Approved investigations vendor serving Fort Bend County’s expanding criminal docket. Full bilingual English/Spanish service capacity available for all Fort Bend matters.
Credibility Technology

EyeDetect® Credibility Assessment

EyeDetect® is a patented credibility assessment technology by Converus that measures involuntary eye behavior — pupil dilation, blink rate, and reading patterns — while a subject answers a series of questions. Unlike polygraph, it is non-invasive, requires no physical attachment, and produces a digitally scored result.

IAI has two Converus-certified EyeDetect® Examiners on staff — one of only a handful of firms in the Houston area with this capability. We administer examinations for defense preparation, client screening, informant challenge, and PCSOT court-required testing.

Pre-Trial
Test your client’s account before committing to a defense theory or advising on a plea.
Mitigation
Demonstrate credibility and cooperation to prosecutors or sentencing judges.
Informant Challenge
Test the credibility of cooperating witnesses whose testimony is central to the prosecution.
PCSOT
Post-Conviction Sex Offender Testing — court-required in many supervision conditions.
95%
Accuracy Rate
30
Min. Test Time
2
Certified Examiners
0
Physical Contact
The IAI Team

Licensed. Credentialed. Court-Ready.

Every IAI engagement is handled by licensed, credentialed professionals with real-world backgrounds in law enforcement, corrections, and behavioral science.

CGW
Dr. Celvin G. Walwyn, Ph.D.
Executive Director & Lead Investigator
  • Retired International Police Commissioner
  • Retired Texas Police Chief (2026)
  • Ph.D. Public Safety Leadership — Summa Cum Laude
  • Certified EyeDetect® Examiner (Converus)
  • PCSOT Certified
  • Active TCOLE Master Peace Officer License
  • Licensed Private Investigator (TX)
  • CJA Panel Vendor
  • Bilingual: English & Spanish
ADW
A.D. Walwyn, M.Sc.
Owner & Senior Investigator
  • Licensed Private Investigator (TX, since 2021)
  • M.Sc., Security Management
  • Certified EyeDetect® Examiner (Converus)
  • 12 Years — Harris County Corrections
  • Bilingual: English & Spanish
  • Minority Women-Owned Business Owner
EAC
Earl A. Campbell, B.Sc.
Investigator
  • Licensed Private Investigator (TX)
  • 5 Years Investigative Experience
  • B.Sc., Psychology
  • Specialization: Mental Health Counseling
Getting Started

How to Work With IAI

Simple, fast, and designed around how defense practitioners actually work.

01
Initial Consultation
Call or email IAI. Describe your case and what you need. We will tell you within 24 hours whether we can help and what it will take.
02
Execute Retainer
Sign the IAI Retainer Agreement digitally. Investigative services: $200/hr (10-hour minimum). Consulting: $300/hr (10-hour minimum). Work begins upon receipt.
03
Investigation & Documentation
We conduct the investigation and produce a written report that meets your evidentiary standards — court-ready, professionally documented, and delivered on time.
04
Expert Support
Dr. Walwyn is available for affidavits, deposition preparation, and expert testimony on law enforcement procedure, use of force, and agency policy compliance.
Case Referral

Refer a Case to IAI

Use this form to submit a case referral or consultation request to IAI. We respond to all inquiries within one business day. For urgent matters, call (407) 341-2778 directly.

Court-appointed counsel in the SDTX, Harris County, and Fort Bend County can retain IAI directly through the CJA panel process. Include your case number and assigned judge and we will handle the authorization process.

Fee Schedule

Investigative Services: $200/hour · 10-hour minimum ($2,000)
Consulting Services: $300/hour · 10-hour minimum ($3,000)

IAI pauses at the 10-hour minimum and awaits your authorization before continuing.

Ready to Give Your Client
The Investigative Advantage?

IAI is a CJA Panel Vendor in the Southern District of Texas, Harris County, and Fort Bend County. Court-appointed counsel can retain IAI directly. Private retained counsel is welcome.

Execute Retainer Agreement Email IAI (407) 341-2778