Court-appointed expert in information technology
Noise is not evidence.
Between the mass of data in a case file and a finding a court can actually rely on lies technical work — and someone who answers for it. Thirty-five years at the bench in technology, legal training, and the accountability of the person who signs the report.
- Court expert
- TJRJ No. 10,650
- Attorney
- Brazilian Bar RJ 188,310
- Federal Courts
- Accredited on eproc — TRF2
- Jurisdiction
- Rio de Janeiro and metropolitan area
An expert must understand technology.
He must also understand procedure.
Signed by
Heron Simões Mattos
Court Expert TJRJ No. 10,650
Accredited on eproc — Federal Courts, 2nd Region
Attorney — Brazilian Bar RJ 188,310
Rio de Janeiro
I am a court-appointed expert in information technology registered with the Rio de Janeiro Court of Justice and accredited on eproc, the electronic case system of the Brazilian Federal Courts for the 2nd Region, an attorney admitted to the Brazilian Bar, and an IT entrepreneur of more than thirty-five years. That combination is uncommon, and it changes the outcome of the work.
A report can be technically correct and procedurally useless: it answers the topic rather than the question actually put to the expert. It can equally be legally elegant and technically weak, because whoever wrote it never opened the equipment. What I deliver sits at the meeting point of those two requirements — a verifiable technical answer, in the form the proceedings will accept.
I began in electronics: a technical degree in Electronics through the CEFET programme and eight semesters of Electronic Engineering at the same institution. That changes how equipment is examined — someone who has studied circuits distinguishes a manufacturing defect from misuse by looking at the board, not merely by reading the service centre report. Law came later, and computing in between.
As Chief Technology Officer of HM-TI Consult I have been an authorised representative of Microsoft, Cisco, Apple and HP since 2008 — with direct command of licensing, hardware architecture and the manufacturers’ support chain. As founding partner of Mattos & Mattos Advogados I have run a caseload of roughly one to two thousand matters since 2013. Legal training includes an LL.M. in Business Law from FGV and an MBA in Strategic Management from UFF.
A report that is technically correct and procedurally usable answers the question put to the expert, not the topic.
What I can be appointed for
- 01
Software and licensing
- Damages claims for unlicensed use
- Termination of IT contracts
- Intellectual property and copyright in software
- Criminal software piracy — art. 12 of Law 9,609/98 and art. 184 of the Penal Code
- 02
Computer forensics
- Examination of computers, phones and media
- Stored material and deleted files
- Unauthorised device access
- Chain of custody — arts. 158-A to 158-F of the Code of Criminal Procedure
- 03
Digital evidence and fraud
- Authenticity of messages and screenshots
- Family, child protection and domestic violence
- Bank liability claims
- Electronic fraud
- 04
Hardware and equipment
- Consumer claims
- Statutory and contractual warranty
- Sale of goods
- Insurance claims
- 05
Networks, systems and infrastructure
- IT and outsourcing contracts
- Civil liability
- Commercial disputes
- 06
Artificial intelligence and data protection
- Data protection (LGPD)
- Image and reputation rights
- Consumer relations
- Review of automated decisions
- Employment disputes
You are not asked to believe it. You are asked to test it.
The chain of custody of digital evidence — governed in Brazil by articles 158-A to 158-F of the Code of Criminal Procedure — depends on being able to demonstrate that the file filed in the record is exactly the file that was seized. The instrument of that demonstration is the cryptographic hash: a fixed-length signature that identifies content in a practically unique way.
Alongside is a working bench. Drop any file onto it and it computes SHA-256 and SHA-1 using your own browser’s Web Crypto API. Then flip a single bit and watch what happens to the result.
No file is sent anywhere. To confirm it, open the developer tools and watch the network tab while you use it — there is no request. That is also a data-protection argument: analysis is possible without processing the data.
Drop a file here — a screenshot, a PDF, a video, anything.
What these tools do — and what they do not
I have used artificial intelligence in expert practice and in legal practice for years, and I have built my own systems on top of it. That lets me discuss the subject without enthusiasm and without panic — on the two points that matter to whoever is instructing: what the technology delivers today, and where it cannot be used at all.
Topic I
Claude, by Anthropic
What it consists of; how context, tools, MCP, agents and skills actually work — and the systems I built with it: the litigation-management platform integrated with the Brazilian National Council of Justice’s public DataJud API, the court-record reading pipeline, and assisted drafting of pleadings.
Open the topicTopic II
The other AIs
GPT (OpenAI), Gemini (Google), open-weight models run locally, and the specialised legal tools. What each is for, what it costs, where it fails — and how one establishes, forensically, whether a given piece of content came out of one of them.
Open the topicMy practice is not limited to expert reports
Deployment and infrastructure
Networks, servers, information security and digital transformation for companies and institutions. Authorised representative of Microsoft, Cisco, Apple and HP since 2008.
Method and process
Design of digital control workflows, document governance and deployment of management systems — including across caseloads of thousands of matters.
Bespoke development
Platforms built in-house: litigation management integrated with the public DataJud API, document management, task boards, deadline calendars, personal-data anonymisation and a client portal.
Data-protection compliance — the technical side
Mapping of processing activities, lawful basis, anonymisation, incident response, and the technical side of bringing notarial and registry offices into compliance with CNJ Provision 134/2022.
Party-appointed technical assistance
Shadowing an examination conducted by another expert, drafting the questions to be put, methodological critique and dissenting technical opinion.
Training and lectures
The real legal impact of AI for lawyers, public administrators and companies — in evidence, contracts, automated decisions and regulatory compliance.
Appointment, instruction or consultation