Harris County Criminal Lawyers Association
Integrity Assessments Investigations

The Defense
Investigator
Advantage

How Command-Level Investigative Expertise
Strengthens Every Criminal Defense Case

When law enforcement investigates — who investigates the investigators? IAI brings decades of command-level experience to every criminal defense case.

Dr. Celvin G. Walwyn, Ph.D.
Executive Director · Integrity Assessments Investigations
Contact IAI Today Meet the Team
Dr. Celvin G. Walwyn
38+
Years Command Experience
iahotx.com
CJA Panel Vendor
TX Lic. A19944401
(407) 341-2778
admin@iahotx.com
The Problem

The Challenge Your Clients Face

When law enforcement investigates — who investigates the investigators?

01
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 where to look.

02
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.

03
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.

Our People

Who We Are

Integrity Assessments Investigations · Minority Women-Owned Business · Harris & Fort Bend County, Texas

Dr. Celvin G. Walwyn
Dr. Celvin G. Walwyn, Ph.D.
Executive Director
  • International Police Commissioner
  • Texas Police Chief (ret.)
  • TCOLE Licensed
  • EyeDetect® Certified Examiner
A.D. Walwyn
A.D. Walwyn, M.Sc.
Owner & Senior Investigator
  • Licensed PI since 2021
  • Harris County Corrections
  • EyeDetect® Certified Examiner
  • Bilingual English / Spanish
Earl A. Campbell
Earl A. Campbell, B.Sc.
Investigator
  • 5 Years Investigative Experience
  • Psychology Background
  • Mental Health Counseling Specialization
Minority Women-Owned CJA Panel Vendor Bilingual EN / ES TX Lic. No. A19944401
Jurisdiction

Tri-Level Court Approval

IAI is court-approved at every level where your clients need investigative support.

01
Federal
U.S. District Court SDTX

CJA Panel Vendor — court-appointed by the Southern District of Texas. Zero bureaucratic friction for appointed defense counsel.

CJA Panel Vendor
02
District
Harris County District Courts

Approved investigations vendor. 12 years of insider knowledge of Harris County Corrections — booking, release, and institutional processes.

Approved Vendor
03
County
Fort Bend County Courts

Approved investigations vendor serving one of Texas's fastest-growing criminal dockets. Full bilingual service capacity.

Approved Vendor
Capabilities

What a Defense Investigator Actually Does for Your Case

Most attorneys underutilize investigators. Here is the full scope of what IAI brings to your case.

📁
Case File Review

We read the entire file — police reports, body cam logs, chain of custody records — looking for inconsistencies, policy violations, and constitutional issues.

🔍
Witness Location

We locate and interview witnesses law enforcement may have missed, ignored, or discouraged — building the alternative narrative your client deserves.

📋
Agency Policy Analysis

Every law enforcement agency has written SOPs. We compare what officers did against what their own policies required — and document every deviation.

👁️
Credibility Assessment

Two certified EyeDetect® Examiners on staff. We evaluate the credibility of your client, witnesses, and informants using Converus technology.

🔎
Background Investigations

We investigate the investigators. Officers, informants, and key witnesses all have histories. We find what matters and document it for court.

⚖️
Expert Testimony

Dr. Walwyn provides expert testimony on law enforcement procedure, use of force, and investigative conduct — with credentials no opposing expert can match.

Technology

EyeDetect® Credibility Assessment

A scientifically validated alternative — with two certified examiners on the IAI team.

What Is EyeDetect®?

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. It is used by law enforcement agencies, government contractors, and private sector clients worldwide.

IAI has two certified EyeDetect® Examiners on staff — among only a handful of firms in the Houston area with this capability.
How It Helps Your Client
Pre-Trial

Test your client's account before committing to a defense theory.

Mitigation

Demonstrate credibility and cooperation to prosecutors or sentencing judges.

PCSOT

Post-Conviction Sex Offender Testing — court-required in supervision conditions.

Informant Challenge

Test the credibility of cooperating witnesses or informants whose testimony is central to the prosecution.

Real Results

IAI In Action — Case Scenarios

How defense investigators change outcomes.

01
Federal Narcotics
Situation

Client charged in multi-defendant SDTX drug conspiracy. Government's case relies on cooperating witness testimony.

IAI Action

IAI reviews the investigation file and identifies that the lead agent's own agency policy required corroboration of CI information before obtaining the search warrant — a step that was not taken.

Outcome
Suppression motion filed. Evidence challenged. Defense positioned for dismissal or significant reduction.
02
State Assault / Use of Force
Situation

Client arrested after altercation with off-duty officer. Official report narrative conflicts with what witnesses recall.

IAI Action

IAI locates two witnesses law enforcement did not interview. Subject locate investigation confirms both were present. Statements documented and preserved.

Outcome
Defense narrative corroborated by independent witness testimony not in the government's file.
03
Sex Offense / PCSOT
Situation

Client on supervision with PCSOT testing requirement. Prior examiner's results disputed. Client maintains innocence on specific allegations.

IAI Action

IAI administers EyeDetect® examination. Results scored digitally by Converus technology. Report produced and provided to supervising officer and defense counsel.

Outcome
Objective credibility data provided to the court. Supervision conditions addressed with documented evidence.
Why IAI

The Command Difference

What separates IAI from every other investigative firm in Harris County.

38+
Years Combined Experience

Command-level law enforcement experience across three distinct jurisdictions.

3
Jurisdictions

Sovereign nation · U.S. Federal Territory · State of Texas

2×
EyeDetect® Certified

Two Converus-certified examiners on staff — among only a handful of firms in the Houston area.

Ph.D. · Summa Cum Laude Active TCOLE License Minority Women-Owned Business Independently Operated Harris County Certified
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
Case Assignment

We assign the right team member to your matter based on the nature of the case — federal, state, credibility, or subject locate.

03
Investigation & Documentation

We conduct the investigation and produce a written report that meets your evidentiary standards — court-ready, professionally documented.

04
Expert Support

Dr. Walwyn is available for affidavits, deposition preparation, and expert testimony on law enforcement procedure and agency compliance.

Contact IAI

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

Integrity Assessments Investigations
Capability Statement and Bio Sheet available upon request.

Call (407) 341-2778
📞
Phone
(407) 341-2778
✉️
Email
admin@iahotx.com
🌐
Website
iahotx.com
CJA Panel Vendor · SDTX Harris County Approved Fort Bend County Approved TX Lic. A19944401 Minority Women-Owned