Defense Investigations for Harris County, Fort Bend County, and the Southern District of Texas

A former police chief who knows how the State built its case, and where it’s weak.

IAI investigates for criminal defense attorneys. We locate and interview the witnesses the file left out, audit PSI reports before sentencing, and review police work against the agency’s own policies. Approved for appointed cases in federal, Harris, and Fort Bend courts. Bilingual English and Spanish.

Refer a Case Call (346) 517-2517
Attorney Portal

CJA Panel Vendor (SDTX), Harris and Fort Bend appointed-case vendor, Texas PI License A19944401, minority women-owned, English and Español.

Dr. Celvin G. Walwyn
Dr. Celvin G. Walwyn, Ph.D.
Executive Director & Lead Investigator

Former Commissioner of Police (St. Kitts & Nevis), former Deputy Commissioner (U.S. Virgin Islands), retired Texas Police Chief. 38+ years in law enforcement.

38+
Years inside law enforcement
12
Years inside Harris County Corrections (A.D. Walwyn)
3
Court systems approved: federal, Harris, Fort Bend
EN / ES
Interviews in Spanish, no interpreter
Attorney Testimonials

Houston defense attorneys who work with us

“Over the course of dozens of cases, IAI has consistently proven to be an exceptional investigative team… They deliver every single time.”

Zane Weeks, Criminal Defense Attorney, Harris County
Read the full quote

“Over the course of dozens of cases, IAI has consistently proven to be an exceptional investigative team and an invaluable asset to my practice. They deliver every single time. Their work ethic, attention to detail, and ability to move quickly without sacrificing quality have had a tremendous impact on my cases.”

“An essential part of my criminal defense practice across both state felony and federal CJA cases… They are my go-to investigative team.”

Andrew J. Williams, Criminal Defense Attorney, Harris County & SDTX

“I have worked with IAI on numerous MAC cases… I call them my lucky charm — and for good reason.”

Shari McDonough, Criminal Defense Attorney, Harris County

“Dr. Walwyn’s background as a former police chief gives him a unique perspective that benefits every case.”

Shawn Ticer, Ticer Law, Harris County

“A model of ethical, thorough criminal defense investigation.”

Prof. Lydia D. Johnson, TSU Thurgood Marshall School of Law
Why a Former Chief Works for the Defense

I spent 38 years on the other side. I know where cases are weak.

Every case file is assembled under time pressure, by people with caseloads, following procedures that don’t always get followed. As a police chief, I wrote those procedures, trained officers on them, and reviewed the files when they fell short. I know which shortcuts get taken, which witnesses don’t get re-interviewed, and which reports get written after the fact.

Now I bring that knowledge to the defense table.

Dr. Celvin G. Walwyn

Witnesses the file left out

We find and interview the people who were never documented, and preserve their statements before memories fade or they move. In English or Spanish.

Police work measured against policy

Every agency has written policies on searches, interviews, evidence, and use of force. We compare what officers did to what their own rules required.

PSI errors caught before sentencing

Misclassified priors and missing mitigation can add years. We audit the report line by line and give you a written analysis to use in objections.

Refer a Case
Services

What we do for your case

Witness location & interviews
We find witnesses the file left out, interview them, and deliver signed or recorded statements you can use.
PSI review
A line-by-line audit of the pre-sentence report, with a written analysis ready for your objections. Federal and state.
Mitigation investigation
Mental health history, trauma, family, work, and community ties: documented, with witnesses lined up.
Police policy & procedure review
Dr. Walwyn compares officer conduct to the agency’s own written policies and training standards. Available as consulting or expert testimony.
Spanish-language field work
Interviews and statements conducted in Spanish by a licensed bilingual investigator. No interpreter, nothing lost in translation.
Credibility assessment
EyeDetect and VerifEye testing for client screening and case preparation. Details below.
Refer a Case
PSI Review

Sentencing is where years are won or lost. We read the PSI before the judge does.

Pre-sentence reports are built from records and databases that contain errors. A misclassified prior or a missed mitigating factor can move the guideline range by years. Your objection deadline is short. We audit the report fast and give you a written analysis you can use directly.

Turnaround: We begin the analysis as soon as the retainer or funding approval is received.

Federal (U.S. Sentencing Guidelines) and state cases. Available to appointed counsel through CJA and county funding.

Request a PSI Review
Criminal history audit
Every prior verified for jurisdiction, offense level, disposition, and how it was scored.
Factual error list
Each inaccuracy, with the source showing the correct fact.
Mitigation findings
What the report left out, with documents and witnesses to support it.
Written analysis
Organized to match your objections, ready to file or argue from.
EyeDetect & VerifEye

Credibility testing: know what your client’s story is worth before the State tests it.

EyeDetect and VerifEye, developed by Converus, measure involuntary eye behavior while the subject answers specific questions about the case. There are no wires or sensors. An EyeDetect test takes 20 to 30 minutes in our office; a VerifEye test takes about 10 minutes remotely by smartphone, which works for detained clients and out-of-town witnesses.

How attorneys use it

What it is and isn’t

AccuracyConverus reports 86–91% for EyeDetect depending on the test type, and 80%+ for VerifEye under standard conditions.
In courtResults are generally not admitted as trial evidence in Texas. They are a strategy and negotiation tool. One New Mexico court admitted EyeDetect results in 2018; admissibility is still debated.
What it measuresTruthfulness on specific questions. It does not measure remorse, character, or future risk.
Who testsDr. Walwyn is a Converus-certified EyeDetect examiner (in-office, computer-based test). Dr. Walwyn, A.D. Walwyn, and Ty Walwyn are certified VerifEye specialists (remote test).

Pricing

EyeDetect test (in office)$300
VerifEye remote test$250
VerifEye sentencing report (test + court-formatted report)$450
Multiple subjects or federal mattersCustom quote
Book a Test Watch a VerifEye demo (video)

Sources: Converus FAQ and ABA Journal: a law professor’s view on EyeDetect in court.

The Team

Who works your case

Dr. Celvin G. Walwyn
Dr. Celvin G. Walwyn, Ph.D.
Executive Director & Lead Investigator

Dr. Walwyn has led police agencies at every level: Commissioner of Police for the Federation of St. Kitts and Nevis, Deputy Commissioner of the U.S. Virgin Islands Police Department, and Texas Police Chief. He wrote and enforced the policies he now reviews for the defense. Ph.D. in Public Safety Leadership (Summa Cum Laude). Bill Blackwood LEMIT graduate. Active TCOLE Master Peace Officer License. Licensed Texas PI. Certified EyeDetect examiner and VerifEye specialist. Bilingual.

A.D. Walwyn
A.D. Walwyn, M.Sc.
Owner & Senior Investigator

A.D. spent 12 years inside Harris County Corrections managing inmate booking and release. She knows how the jail works, how to get access, and how detained clients are processed, which saves attorneys time on every in-custody case. Licensed Texas PI since 2021. M.Sc. in Security Management. Certified VerifEye specialist. Conducts interviews in Spanish.

Earl A. Campbell
Earl A. Campbell, B.Sc.
Investigator

Earl brings a psychology and mental health counseling background to witness interviews and mitigation work, especially where mental health is part of the case. Licensed Texas PI. 5 years of investigative experience.

Ty Walwyn
Ty Walwyn
Certified VerifEye Specialist

Ty administers remote VerifEye assessments, including for detained clients and out-of-county witnesses. Converus-certified.

Jessica Doyle
Jessica Doyle
Investigator

Jessica is IAI’s lead bilingual investigator. Spanish is her first language, so Spanish-speaking witnesses and families are interviewed directly, with nothing lost in translation. Licensed Texas PI.

With five licensed and certified team members, your case keeps moving even when one of us is in court or in the field.

Appointed Cases

Appointed on the case? We make the funding request easy.

IAI is an approved vendor for appointed defense work in the Southern District of Texas (CJA Panel), Harris County, and Fort Bend County. Send us the case details and we’ll return a cost estimate and a scope of work you can attach to your funding request. We respond within 24 hours.

  1. Email admin@iahotx.com or use Refer a Case with the cause number, court, and what you need.
  2. We send a cost estimate and scope of work for your funding request.
  3. Once funding is approved, we start, and you get regular updates through the attorney portal.
Southern District of Texas
CJA Panel Vendor. Houston, Galveston, Laredo, and Corpus Christi divisions.
Harris County
Approved vendor for appointed criminal defense.
Fort Bend County
Approved vendor for appointed criminal defense in county and district courts.

Retained counsel: we work on retainer. Download our retainer agreement or call (346) 517-2517 to discuss scope.

FAQ

Questions attorneys ask us

How fast can you start?
Most cases start within 4 business days of the signed order or retainer. Time-sensitive work, like preserving video or reaching a witness before they leave, starts within 48 hours.
You’re a former police chief. Whose side are you on?
Yours. Once retained, we work for the defense and report only to you. Knowing how police build cases is exactly why defense attorneys hire us.
Is our work product protected?
We work at your direction, report only to you, and don’t share findings with anyone else. Talk to us about how you want reports handled before we write anything down.
Do you testify?
Yes. Dr. Walwyn is available as an expert on police procedure, use of force, and agency policy compliance, and our investigators testify about their findings when needed.
Can you visit clients in jail?
Yes. We’re approved to enter local county jails and federal detention facilities. A.D. Walwyn’s 12 years in Harris County Corrections make jail access faster.
Is EyeDetect admissible?
Generally not as trial evidence in Texas. Attorneys use it to evaluate a client’s account, prepare for plea talks, and support sentencing materials.
Do you offer polygraph?
No. Our credibility testing uses EyeDetect and VerifEye, and our examiners are certified through Converus.
Do you work in Spanish?
Yes. Interviews, statements, and documentation in Spanish, by a licensed investigator. No interpreter.
Are you a minority women-owned business?
Yes. IAI is 51% owned by A.D. Walwyn. We don’t currently hold a formal MWBE or HUB certification, so ask us first if your procurement process requires one.
Refer a Case

Refer a case

Tell us about the case and we’ll reply within 24 hours.

TX PI License
A19944401
Courts
Southern District of Texas, Harris County, Fort Bend County
Retainer Agreement TX DPS Consumer Complaint Notice
Don’t include privileged details here. We’ll follow up by phone.